#include <bits/stdc++.h>
using namespace std;
static const int MOD = 1000000007;
static const long long MODL = 1000000000000000003LL;
static const double eps = 1e-8;
template <class T>
inline T MIN(const T x, const T y) {
  return (x < y) ? x : y;
}
template <class T>
inline T MAX(const T x, const T y) {
  return (x > y) ? x : y;
}
template <class T>
inline void UPDMIN(T &x, const T y) {
  if (x > y) x = y;
}
template <class T>
inline void UPDMAX(T &x, const T y) {
  if (x < y) x = y;
}
template <class T>
inline int SIZE(const T &x) {
  return (int)x.size();
}
template <class T>
inline int LENGTH(const T &x) {
  return (int)x.length();
}
template <class T1, class T2>
inline pair<T1, T2> MP(const T1 &x, const T2 &y) {
  return make_pair(x, y);
}
inline int BINT(const int x) { return 1 << x; }
inline long long BLLD(const int x) { return 1LL << x; }
inline int BINT_TEST(const int s, const int x) { return (s & BINT(x)) != 0; }
inline int BLLD_TEST(const long long s, const int x) {
  return (s & BLLD(x)) != 0LL;
}
template <class T>
inline T LOWBIT(const T x) {
  return (x ^ (x - 1)) & x;
}
template <class T>
inline int BITCOUNT(const T x) {
  return (!x) ? x : (1 + BITCOUNT(x & (x - 1)));
}
const double PI = acos(-1.0);
const double EPS = 1e-5;
template <class T>
inline T SQR(const T x) {
  return x * x;
}
template <class T1, class T2>
inline T1 POW(const T1 x, const T2 y) {
  if (!y)
    return 1;
  else if ((y & 1) == 0) {
    return SQR(POW(x, y >> 1));
  } else
    return POW(x, y ^ 1) * x;
}
template <class T>
inline T GCD(const T x, const T y) {
  if (x < 0) return GCD(-x, y);
  if (y < 0) return GCD(x, -y);
  return (!y) ? x : GCD(y, x % y);
}
template <class T>
inline T LCM(const T x, const T y) {
  if (x < 0) return LCM(-x, y);
  if (y < 0) return LCM(x, -y);
  return x * (y / GCD(x, y));
}
template <class T>
inline T EEA(const T a, const T b, T &x, T &y) {
  if (a < 0) {
    T d = EEA(-a, b, x, y);
    x = -x;
    return d;
  }
  if (b < 0) {
    T d = EEA(a, -b, x, y);
    y = -y;
    return d;
  }
  if (!b) {
    x = 1;
    y = 0;
    return a;
  } else {
    T d = EEA(b, a % b, x, y);
    T t = x;
    x = y;
    y = t - (a / b) * y;
    return d;
  }
}
template <class T>
inline vector<pair<T, int> > FACTORIZE(T x) {
  vector<pair<T, int> > ret;
  if (x < 0) x = -x;
  for (T i = 2; x > 1;) {
    if (x % i == 0) {
      int count = 0;
      for (; x % i == 0; x /= i) count++;
      ret.push_back(MP(i, count));
    }
    i++;
    if (i > x / i) i = x;
  }
  return ret;
}
template <class T>
inline int ISPRIME(const T x) {
  if (x <= 1) return 0;
  for (T i = 2; SQR(i) <= x; i++)
    if (x % i == 0) return 0;
  return 1;
}
template <class T>
inline T EULARFUNCTION(T x) {
  vector<pair<T, int> > f = FACTORIZE(x);
  for (typename vector<pair<T, int> >::iterator it = f.begin(); it != f.end();
       it++) {
    x = x / it->first * (it->first - 1);
  }
  return x;
}
template <class T>
inline T INVERSEE(const T a, const T b = MOD) {
  T x, y;
  EEA(a, b, x, y);
  return x ? x : 1;
}
int *PRIMELIST(const int til, int *length = NULL) {
  int *foo = (int *)malloc(sizeof(int) * (til + 1));
  int len = 0;
  memset(foo, 0, sizeof(int) * (til + 1));
  for (int i = 2; i <= til; i++) {
    if (!foo[i]) foo[len++] = i;
    for (int j = 0; j < len && foo[j] <= til / i; j++) {
      foo[foo[j] * i] = 1;
      if (i % foo[j] == 0) break;
    }
  }
  if (length != NULL) {
    *length = len;
  }
  foo[len++] = 0;
  foo = (int *)realloc(foo, sizeof(int) * len);
  return foo;
}
template <class T>
inline T MOD_STD(const T x, const T m = MOD) {
  return (x % m + m) % m;
}
template <class T>
inline void MOD_STD(T *x, const T m = MOD) {
  *x = (*x % m + m) % m;
}
template <class T>
inline T MOD_ADD(const T x, const T y, const T m = MOD) {
  return (x + y) % m;
}
template <class T>
inline void MOD_ADD(T *x, const T y, const T m = MOD) {
  *x = (*x + y) % m;
}
template <class T>
inline T MOD_MUL(const T x, const T y, const T m = MOD) {
  return (T)((1LL * x * y) % m);
}
template <class T>
inline void MOD_MUL(T *x, const T y, const T m = MOD) {
  *x = (T)((1LL * (*x) * y) % m);
}
template <class T1, class T2>
inline T1 MOD_POW(const T1 x, const T2 y, const T1 m = MOD) {
  if (y == 0)
    return 1 % m;
  else if ((y & 1) == 0) {
    T1 z = MOD_POW(x, y >> 1, m);
    return MOD_MUL(z, z, m);
  } else
    return MOD_MUL(MOD_POW(x, y ^ 1, m), x, m);
}
inline long long MODL_MUL(long long x, long long y, const long long m = MOD) {
  if (x < y) swap(x, y);
  long long z = 0LL;
  while (y > 0) {
    if (y & 1) {
      MOD_ADD(&z, x, m);
    }
    MOD_ADD(&x, x, m);
    y >>= 1;
  }
  return z;
}
inline long long MODL_POW(const long long x, const long long y,
                          const long long m = MOD) {
  if (y == 0LL)
    return 1LL % m;
  else if ((y & 1) == 0LL) {
    long long z = MODL_POW(x, y >> 1, m);
    return MODL_MUL(z, z, m);
  } else
    return MODL_MUL(MODL_POW(x, y ^ 1, m), x, m);
}
template <class T>
class MATX {
 private:
  unsigned long hig, wid;
  T *data;
  void __init() {
    this->data = (T *)malloc(sizeof(T) * this->hig * this->wid);
    memset(this->data, 0, sizeof(T) * this->hig * this->wid);
  }

 public:
  MATX() {
    this->hig = this->wid = 1;
    __init();
  }
  MATX(const unsigned long _len) {
    this->hig = this->wid = _len;
    __init();
  }
  MATX(const unsigned long _hig, const unsigned long _wid) {
    this->hig = _hig;
    this->wid = _wid;
    __init();
  }
  MATX(const MATX &rhs) {
    this->hig = rhs.hig;
    this->wid = rhs.wid;
    this->data = (T *)malloc(sizeof(T) * this->hig * this->wid);
    for (unsigned long x = 0; x < this->hig; x++)
      for (unsigned long y = 0; y < this->wid; y++)
        this->data[x * this->wid + y] = rhs.at(x, y);
  }
  ~MATX() { free(this->data); }
  T &operator()(const unsigned long x, const unsigned long y) {
    if (x >= this->hig || y >= this->wid) return (*(T *)NULL);
    return this->data[x * this->wid + y];
  }
  T *operator[](const unsigned long x) {
    if (x >= this->hig) return (T *)NULL;
    return this->data + (x * this->wid);
  }
  MATX &operator=(const MATX &rhs) {
    if (this->hig != rhs.hig || this->wid != rhs.wid) {
      free(this->data);
      this->hig = rhs.hig;
      this->wid = rhs.wid;
      this->data = (T *)malloc(sizeof(T) * this->hig * this->wid);
    }
    for (unsigned long x = 0; x < this->hig; x++)
      for (unsigned long y = 0; y < this->wid; y++)
        this->data[x * this->wid + y] = rhs.at(x, y);
    return *this;
  }
  const MATX operator+(const MATX &opn) const {
    MATX ret(*this);
    for (unsigned long x = 0; x < ret.hig; x++)
      for (unsigned long y = 0; y < ret.wid; y++)
        ret.data[x * ret.wid + y] += opn.at(x, y);
    return ret;
  }
  const MATX operator-(const MATX &opn) const {
    MATX ret(*this);
    for (unsigned long x = 0; x < ret.hig; x++)
      for (unsigned long y = 0; y < ret.wid; y++)
        ret.data[x * ret.wid + y] -= opn.at(x, y);
    return ret;
  }
  const MATX operator*(const MATX &opn) const {
    MATX ret(this->hig, opn.wid);
    const unsigned long len = MIN(this->wid, opn.hig);
    for (unsigned long x = 0; x < ret.hig; x++)
      for (unsigned long y = 0; y < ret.wid; y++)
        for (unsigned long z = 0; z < len; z++)
          ret.data[x * ret.wid + y] += this->at(x, z) * opn.at(z, y);
    return ret;
  }
  const MATX mul(const MATX &opn) const { return *this * opn; }
  template <class T2>
  const MATX mul(const MATX &opn, const T2 m) const {
    MATX ret(this->hig, opn.wid);
    const unsigned long len = MIN(this->wid, opn.wid);
    for (unsigned long x = 0; x < ret.hig; x++)
      for (unsigned long y = 0; y < ret.wid; y++)
        for (unsigned long z = 0; z < len; z++)
          MOD_ADD(&ret.data[x * ret.wid + y],
                  MOD_MUL(this->at(x, z), opn.at(z, y), m), m);
    return ret;
  }
  MATX &operator+=(const MATX &rhs) {
    *this = *this + rhs;
    return *this;
  }
  MATX &operator-=(const MATX &rhs) {
    *this = *this - rhs;
    return *this;
  }
  MATX &operator*=(const MATX &rhs) {
    *this = *this * rhs;
    return *this;
  }
  const MATX pow(const unsigned long p) const {
    MATX buff(*this), ret(this->hig, this->wid);
    ret.set_one();
    if (p > 0)
      for (unsigned long i = 1;; i <<= 1) {
        if (p & i) ret *= buff;
        buff *= buff;
        if (i > (p >> 1)) break;
      }
    return ret;
  }
  template <class T2>
  const MATX pow(const unsigned long p, const T2 m) const {
    MATX buff(*this), ret(this->hig, this->wid);
    ret.set_one();
    if (p > 0)
      for (unsigned long i = 1;; i <<= 1) {
        if (p & i) ret = ret.mul(buff, m);
        buff = buff.mul(buff, m);
        if (i > (p >> 1)) break;
      }
    return ret;
  }
  const T at(const unsigned long x, const unsigned long y) const {
    if (x >= this->hig || y >= this->wid) return 0;
    return this->data[x * wid + y];
  }
  void show() const {
    for (unsigned long x = 0; x < this->hig; x++) {
      for (unsigned long y = 0; y < this->wid; y++)
        cout << this->at(x, y) << " ";
      cout << endl;
    }
  }
  void set_one() {
    for (unsigned long x = 0; x < this->hig; x++)
      for (unsigned long y = 0; y < this->wid; y++)
        this->data[x * this->wid + y] = (x == y) ? 1 : 0;
  }
};
template <class T>
class complex_t {
 public:
  T r, i;
  complex_t(T x = 0.0, T y = 0.0) {
    this->r = x;
    this->i = y;
  }
  complex_t operator+(const complex_t &opn) const {
    return complex_t(this->r + opn.r, this->i + opn.i);
  }
  complex_t operator-(const complex_t &opn) const {
    return complex_t(this->r - opn.r, this->i - opn.i);
  }
  complex_t operator*(const complex_t &opn) const {
    return complex_t(this->r * opn.r - this->i * opn.i,
                     this->r * opn.i + this->i * opn.r);
  }
};
template <class T>
void fast_fourier_trans(complex_t<T> f[], const int len, const int is_dft) {
  for (int i = 1, j = len >> 1; i < len - 1; i++) {
    if (i < j) swap(f[i], f[j]);
    int k = len >> 1;
    while (j >= k) {
      j -= k;
      k >>= 1;
    }
    if (j < k) j += k;
  }
  for (int h = 2; h <= len; h <<= 1) {
    complex_t<T> wn(cos(is_dft ? (-2 * PI / h) : (2 * PI / h)),
                    sin(is_dft ? (-2 * PI / h) : (2 * PI / h)));
    for (int i = 0; i < len; i += h) {
      complex_t<T> wm(1.0, 0.0);
      for (int j = i; j < i + (h >> 1); j++) {
        complex_t<T> u = f[j];
        complex_t<T> t = wm * f[j + (h >> 1)];
        f[j] = u + t;
        f[j + (h >> 1)] = u - t;
        wm = wm * wn;
      }
    }
  }
  if (!is_dft) {
    for (int i = 0; i < len; i++) f[i].r /= len * 1.0;
  }
}
class MILLERRABIN {
 private:
  static const int prime_table[12];
  int witness(long long a, long long d, long long s, long long n) {
    long long r = MODL_POW(a, d, n);
    if (r == 1 || r == n - 1) return 0;
    for (int i = 0; i < s - 1; i++) {
      r = MODL_MUL(r, r, n);
      if (r == 1) return 1;
      if (r == n - 1) return 0;
    }
    return 1;
  }

 public:
  int test(const long long n) {
    if (n <= 2LL) return 0;
    long long p = n - 1LL, s = 0LL;
    while (!(p & 1)) {
      p >>= 1;
      s++;
    }
    for (int i = 0; i < 12 && this->prime_table[i] < n; i++) {
      if (witness(this->prime_table[i], p, s, n)) return 0;
    }
    return 1;
  }
};
const int MILLERRABIN::prime_table[12] = {2,  3,  5,  7,  11, 13,
                                          17, 19, 23, 29, 31, 37};
template <class T>
inline int fsign(const T x) {
  if (x > -eps && x < eps) return 0;
  return (x < 0.0) ? -1 : 1;
}
template <class T>
class point_t {
 public:
  T x, y;
  point_t() {
    this->x = 0.0;
    this->y = 0.0;
  }
  point_t(const T _x, const T _y) {
    this->x = _x;
    this->y = _y;
  }
  point_t operator-(const point_t &rhs) const {
    return point_t(this->x - rhs.x, this->y - rhs.y);
  }
  T operator^(const point_t &rhs) const {
    return this->x * rhs.y - this->y * rhs.x;
  }
  T operator*(const point_t &rhs) const {
    return this->x * rhs.x + this->y * rhs.y;
  }
  bool operator<(const point_t &rhs) const {
    if (fsign(this->y - rhs.y) != 0) return fsign(this->y - rhs.y) < 0;
    return fsign(this->x - rhs.x) < 0;
  }
  T cross(const point_t &p, const point_t &q) const {
    return (p - *this) ^ (q - *this);
  }
  void rotate(const double radian) {
    T x0 = x, y0 = y;
    T sinr = sin(radian);
    T cosr = cos(radian);
    x = x0 * cosr - y0 * sinr;
    y = x0 * sinr + y0 * cosr;
  }
  void rotate(const point_t &p, const double radian) {
    T x0 = x - p.x, y0 = y - p.y;
    T sinr = sin(radian);
    T cosr = cos(radian);
    x = x0 * cosr - y0 * sinr + p.x;
    y = x0 * sinr + y0 * cosr + p.y;
  }
  T dist2(const point_t &lhs, const point_t &rhs) const {
    return (lhs - rhs) * (lhs - rhs);
  }
  T dist2(const point_t &rhs) const { return (*this - rhs) * (*this - rhs); }
  T dist(const point_t &lhs, const point_t &rhs) const {
    return sqrt((lhs - rhs) * (lhs - rhs));
  }
  T dist(const point_t &rhs) const {
    return sqrt((*this - rhs) * (*this - rhs));
  }
};
template <class T>
class segment_t {
 public:
  point_t<T> p, q;
  segment_t() {
    this->p.x = this->p.y = 0.0;
    this->q.x = this->q.y = 0.0;
  }
  template <class T2>
  segment_t(const point_t<T2> &_p, const point_t<T2> &_q) {
    this->p.x = _p.x;
    this->p.y = _p.y;
    this->q.x = _q.x;
    this->q.y = _q.y;
  }
  segment_t(const T px, const T py, const T qx, const T qy) {
    this->p.x = px;
    this->p.y = py;
    this->q.x = qx;
    this->q.y = qy;
  }
  T length() const { return this->p.dist(this->q); }
  T length2() const { return this->p.dist2(this->q); }
  int contain(const point_t<T> &pnt, const int ignore_endpoint = 0) const {
    if (ignore_endpoint) {
      return fsign((this->p - pnt) ^ (this->q - pnt)) == 0 &&
             fsign((pnt.x - this->p.x) * (pnt.x - this->q.x)) < 0 &&
             fsign((pnt.y - this->p.y) * (pnt.y - this->q.y)) < 0;
    } else {
      return fsign((this->p - pnt) ^ (this->q - pnt)) == 0 &&
             fsign((pnt.x - this->p.x) * (pnt.x - this->q.x)) <= 0 &&
             fsign((pnt.y - this->p.y) * (pnt.y - this->q.y)) <= 0;
    }
  }
  int intersection(const segment_t &sa, const segment_t &sb,
                   const int ignore_endpoint = 0) const {
    if (!ignore_endpoint) {
      if (sa.contain(sb.p) || sa.contain(sb.q) || sb.contain(sa.p) ||
          sb.contain(sa.q))
        return 1;
    }
    return fsign(sa.p.cross(sa.q, sb.p)) * fsign(sa.p.cross(sa.q, sb.q)) < 0 &&
           fsign(sb.p.cross(sb.q, sa.p)) * fsign(sb.p.cross(sb.q, sa.q)) < 0;
  }
  int intersection(const segment_t &rhs, const int ignore_endpoint = 0) const {
    return this->intersection(*this, rhs, ignore_endpoint);
  }
};
template <class T>
static int compare_pas(const void *x, const void *y, void *z) {
  const point_t<T> *p1 = (point_t<T> *)x;
  const point_t<T> *p2 = (point_t<T> *)y;
  const point_t<T> *p0 = (point_t<T> *)z;
  int sgn = fsign(((*p1) - (*p0)) ^ ((*p2) - (*p0)));
  if (sgn != 0) return -sgn;
  return fsign(p0->dist2(*p1) - p0->dist2(*p2));
}
template <class T>
void polar_angle_sort(point_t<T> *pnts, const int n) {
  int p = 0;
  for (int i = 1; i < n; i++) {
    if (pnts[p] < pnts[i]) p = i;
  }
  swap(pnts[0], pnts[p]);
  qsort_r(pnts + 1, n - 1, sizeof(point_t<T>), compare_pas<T>, pnts);
}
template <class T>
void graham(point_t<T> *pnts, const int n, int *idx, int &m) {
  polar_angle_sort(pnts, n);
  m = 0;
  if (n < 3) return;
  idx[m++] = 0;
  idx[m++] = 1;
  for (int i = 2; i < n; i++) {
    while (m > 1 &&
           fsign(pnts[idx[m - 2]].cross(pnts[idx[m - 1]], pnts[i])) <= 0)
      m--;
    idx[m++] = i;
  }
}
int n, m;
int src[1100000], dst[1100000], eid;
int col[1100000], det[1100000];
long long ans;
inline int find(const int u) {
  if (col[u] != u) col[u] = find(col[u]);
  return col[u];
}
int main() {
  ios_base::sync_with_stdio(0);
  while (cin >> n >> m) {
    for (int i = 0; i < n; i++) col[i] = -1;
    eid = 0;
    for (int i = 0; i < m; i++) {
      int u, v;
      cin >> u >> v;
      u--;
      v--;
      col[u] = u;
      col[v] = v;
      if (u == v) continue;
      src[eid] = u;
      dst[eid] = v;
      eid++;
    }
    ans = m * 1LL * (m - 1LL);
    for (int i = 0; i < eid; i++) {
      int u = src[i];
      int v = dst[i];
      if (find(u) != find(v)) {
        col[find(v)] = find(u);
      }
    }
    int vrt = -1;
    for (int i = 0; i < n; i++) {
      if (!~col[i]) continue;
      if (!~vrt) {
        vrt = find(i);
      } else {
        if (vrt != find(i)) {
          ans = 0LL;
          break;
        }
      }
    }
    if (ans) {
      for (int i = 0; i < n; i++) det[i] = 0;
      for (int i = 0; i < eid; i++) {
        int u = src[i];
        int v = dst[i];
        det[u]++;
        det[v]++;
      }
      for (int i = 0; i < eid; i++) {
        int u = src[i];
        int v = dst[i];
        ans -= (eid - (det[u] - 1) - (det[v] - 1) - 1) * 1LL;
      }
      ans >>= 1;
    }
    cout << ans << endl;
  }
  return 0;
}

### Prompt

Please create a solution in Cpp to the following problem:

Little boy Igor wants to become a traveller. At first, he decided to visit all the cities of his motherland — Uzhlyandia.

It is widely known that Uzhlyandia has n cities connected with m bidirectional roads. Also, there are no two roads in the country that connect the same pair of cities, but roads starting and ending in the same city can exist. Igor wants to plan his journey beforehand. Boy thinks a path is good if the path goes over m - 2 roads twice, and over the other 2 exactly once. The good path can start and finish in any city of Uzhlyandia.

Now he wants to know how many different good paths are in Uzhlyandia. Two paths are considered different if the sets of roads the paths goes over exactly once differ. Help Igor — calculate the number of good paths.

Input

The first line contains two integers n, m (1 ≤ n, m ≤ 106) — the number of cities and roads in Uzhlyandia, respectively.

Each of the next m lines contains two integers u and v (1 ≤ u, v ≤ n) that mean that there is road between cities u and v.

It is guaranteed that no road will be given in the input twice. That also means that for every city there is no more than one road that connects the city to itself.

Output

Print out the only integer — the number of good paths in Uzhlyandia.

Examples

Input

5 4
1 2
1 3
1 4
1 5


Output

6

Input

5 3
1 2
2 3
4 5


Output

0

Input

2 2
1 1
1 2


Output

1

Note

In first sample test case the good paths are: 

  * 2 → 1 → 3 → 1 → 4 → 1 → 5, 
  * 2 → 1 → 3 → 1 → 5 → 1 → 4, 
  * 2 → 1 → 4 → 1 → 5 → 1 → 3, 
  * 3 → 1 → 2 → 1 → 4 → 1 → 5, 
  * 3 → 1 → 2 → 1 → 5 → 1 → 4, 
  * 4 → 1 → 2 → 1 → 3 → 1 → 5. 



There are good paths that are same with displayed above, because the sets of roads they pass over once are same: 

  * 2 → 1 → 4 → 1 → 3 → 1 → 5, 
  * 2 → 1 → 5 → 1 → 3 → 1 → 4, 
  * 2 → 1 → 5 → 1 → 4 → 1 → 3, 
  * 3 → 1 → 4 → 1 → 2 → 1 → 5, 
  * 3 → 1 → 5 → 1 → 2 → 1 → 4, 
  * 4 → 1 → 3 → 1 → 2 → 1 → 5, 
  * and all the paths in the other direction. 



Thus, the answer is 6.

In the second test case, Igor simply can not walk by all the roads.

In the third case, Igor walks once over every road.

### Response

```cpp
#include <bits/stdc++.h>
using namespace std;
static const int MOD = 1000000007;
static const long long MODL = 1000000000000000003LL;
static const double eps = 1e-8;
template <class T>
inline T MIN(const T x, const T y) {
  return (x < y) ? x : y;
}
template <class T>
inline T MAX(const T x, const T y) {
  return (x > y) ? x : y;
}
template <class T>
inline void UPDMIN(T &x, const T y) {
  if (x > y) x = y;
}
template <class T>
inline void UPDMAX(T &x, const T y) {
  if (x < y) x = y;
}
template <class T>
inline int SIZE(const T &x) {
  return (int)x.size();
}
template <class T>
inline int LENGTH(const T &x) {
  return (int)x.length();
}
template <class T1, class T2>
inline pair<T1, T2> MP(const T1 &x, const T2 &y) {
  return make_pair(x, y);
}
inline int BINT(const int x) { return 1 << x; }
inline long long BLLD(const int x) { return 1LL << x; }
inline int BINT_TEST(const int s, const int x) { return (s & BINT(x)) != 0; }
inline int BLLD_TEST(const long long s, const int x) {
  return (s & BLLD(x)) != 0LL;
}
template <class T>
inline T LOWBIT(const T x) {
  return (x ^ (x - 1)) & x;
}
template <class T>
inline int BITCOUNT(const T x) {
  return (!x) ? x : (1 + BITCOUNT(x & (x - 1)));
}
const double PI = acos(-1.0);
const double EPS = 1e-5;
template <class T>
inline T SQR(const T x) {
  return x * x;
}
template <class T1, class T2>
inline T1 POW(const T1 x, const T2 y) {
  if (!y)
    return 1;
  else if ((y & 1) == 0) {
    return SQR(POW(x, y >> 1));
  } else
    return POW(x, y ^ 1) * x;
}
template <class T>
inline T GCD(const T x, const T y) {
  if (x < 0) return GCD(-x, y);
  if (y < 0) return GCD(x, -y);
  return (!y) ? x : GCD(y, x % y);
}
template <class T>
inline T LCM(const T x, const T y) {
  if (x < 0) return LCM(-x, y);
  if (y < 0) return LCM(x, -y);
  return x * (y / GCD(x, y));
}
template <class T>
inline T EEA(const T a, const T b, T &x, T &y) {
  if (a < 0) {
    T d = EEA(-a, b, x, y);
    x = -x;
    return d;
  }
  if (b < 0) {
    T d = EEA(a, -b, x, y);
    y = -y;
    return d;
  }
  if (!b) {
    x = 1;
    y = 0;
    return a;
  } else {
    T d = EEA(b, a % b, x, y);
    T t = x;
    x = y;
    y = t - (a / b) * y;
    return d;
  }
}
template <class T>
inline vector<pair<T, int> > FACTORIZE(T x) {
  vector<pair<T, int> > ret;
  if (x < 0) x = -x;
  for (T i = 2; x > 1;) {
    if (x % i == 0) {
      int count = 0;
      for (; x % i == 0; x /= i) count++;
      ret.push_back(MP(i, count));
    }
    i++;
    if (i > x / i) i = x;
  }
  return ret;
}
template <class T>
inline int ISPRIME(const T x) {
  if (x <= 1) return 0;
  for (T i = 2; SQR(i) <= x; i++)
    if (x % i == 0) return 0;
  return 1;
}
template <class T>
inline T EULARFUNCTION(T x) {
  vector<pair<T, int> > f = FACTORIZE(x);
  for (typename vector<pair<T, int> >::iterator it = f.begin(); it != f.end();
       it++) {
    x = x / it->first * (it->first - 1);
  }
  return x;
}
template <class T>
inline T INVERSEE(const T a, const T b = MOD) {
  T x, y;
  EEA(a, b, x, y);
  return x ? x : 1;
}
int *PRIMELIST(const int til, int *length = NULL) {
  int *foo = (int *)malloc(sizeof(int) * (til + 1));
  int len = 0;
  memset(foo, 0, sizeof(int) * (til + 1));
  for (int i = 2; i <= til; i++) {
    if (!foo[i]) foo[len++] = i;
    for (int j = 0; j < len && foo[j] <= til / i; j++) {
      foo[foo[j] * i] = 1;
      if (i % foo[j] == 0) break;
    }
  }
  if (length != NULL) {
    *length = len;
  }
  foo[len++] = 0;
  foo = (int *)realloc(foo, sizeof(int) * len);
  return foo;
}
template <class T>
inline T MOD_STD(const T x, const T m = MOD) {
  return (x % m + m) % m;
}
template <class T>
inline void MOD_STD(T *x, const T m = MOD) {
  *x = (*x % m + m) % m;
}
template <class T>
inline T MOD_ADD(const T x, const T y, const T m = MOD) {
  return (x + y) % m;
}
template <class T>
inline void MOD_ADD(T *x, const T y, const T m = MOD) {
  *x = (*x + y) % m;
}
template <class T>
inline T MOD_MUL(const T x, const T y, const T m = MOD) {
  return (T)((1LL * x * y) % m);
}
template <class T>
inline void MOD_MUL(T *x, const T y, const T m = MOD) {
  *x = (T)((1LL * (*x) * y) % m);
}
template <class T1, class T2>
inline T1 MOD_POW(const T1 x, const T2 y, const T1 m = MOD) {
  if (y == 0)
    return 1 % m;
  else if ((y & 1) == 0) {
    T1 z = MOD_POW(x, y >> 1, m);
    return MOD_MUL(z, z, m);
  } else
    return MOD_MUL(MOD_POW(x, y ^ 1, m), x, m);
}
inline long long MODL_MUL(long long x, long long y, const long long m = MOD) {
  if (x < y) swap(x, y);
  long long z = 0LL;
  while (y > 0) {
    if (y & 1) {
      MOD_ADD(&z, x, m);
    }
    MOD_ADD(&x, x, m);
    y >>= 1;
  }
  return z;
}
inline long long MODL_POW(const long long x, const long long y,
                          const long long m = MOD) {
  if (y == 0LL)
    return 1LL % m;
  else if ((y & 1) == 0LL) {
    long long z = MODL_POW(x, y >> 1, m);
    return MODL_MUL(z, z, m);
  } else
    return MODL_MUL(MODL_POW(x, y ^ 1, m), x, m);
}
template <class T>
class MATX {
 private:
  unsigned long hig, wid;
  T *data;
  void __init() {
    this->data = (T *)malloc(sizeof(T) * this->hig * this->wid);
    memset(this->data, 0, sizeof(T) * this->hig * this->wid);
  }

 public:
  MATX() {
    this->hig = this->wid = 1;
    __init();
  }
  MATX(const unsigned long _len) {
    this->hig = this->wid = _len;
    __init();
  }
  MATX(const unsigned long _hig, const unsigned long _wid) {
    this->hig = _hig;
    this->wid = _wid;
    __init();
  }
  MATX(const MATX &rhs) {
    this->hig = rhs.hig;
    this->wid = rhs.wid;
    this->data = (T *)malloc(sizeof(T) * this->hig * this->wid);
    for (unsigned long x = 0; x < this->hig; x++)
      for (unsigned long y = 0; y < this->wid; y++)
        this->data[x * this->wid + y] = rhs.at(x, y);
  }
  ~MATX() { free(this->data); }
  T &operator()(const unsigned long x, const unsigned long y) {
    if (x >= this->hig || y >= this->wid) return (*(T *)NULL);
    return this->data[x * this->wid + y];
  }
  T *operator[](const unsigned long x) {
    if (x >= this->hig) return (T *)NULL;
    return this->data + (x * this->wid);
  }
  MATX &operator=(const MATX &rhs) {
    if (this->hig != rhs.hig || this->wid != rhs.wid) {
      free(this->data);
      this->hig = rhs.hig;
      this->wid = rhs.wid;
      this->data = (T *)malloc(sizeof(T) * this->hig * this->wid);
    }
    for (unsigned long x = 0; x < this->hig; x++)
      for (unsigned long y = 0; y < this->wid; y++)
        this->data[x * this->wid + y] = rhs.at(x, y);
    return *this;
  }
  const MATX operator+(const MATX &opn) const {
    MATX ret(*this);
    for (unsigned long x = 0; x < ret.hig; x++)
      for (unsigned long y = 0; y < ret.wid; y++)
        ret.data[x * ret.wid + y] += opn.at(x, y);
    return ret;
  }
  const MATX operator-(const MATX &opn) const {
    MATX ret(*this);
    for (unsigned long x = 0; x < ret.hig; x++)
      for (unsigned long y = 0; y < ret.wid; y++)
        ret.data[x * ret.wid + y] -= opn.at(x, y);
    return ret;
  }
  const MATX operator*(const MATX &opn) const {
    MATX ret(this->hig, opn.wid);
    const unsigned long len = MIN(this->wid, opn.hig);
    for (unsigned long x = 0; x < ret.hig; x++)
      for (unsigned long y = 0; y < ret.wid; y++)
        for (unsigned long z = 0; z < len; z++)
          ret.data[x * ret.wid + y] += this->at(x, z) * opn.at(z, y);
    return ret;
  }
  const MATX mul(const MATX &opn) const { return *this * opn; }
  template <class T2>
  const MATX mul(const MATX &opn, const T2 m) const {
    MATX ret(this->hig, opn.wid);
    const unsigned long len = MIN(this->wid, opn.wid);
    for (unsigned long x = 0; x < ret.hig; x++)
      for (unsigned long y = 0; y < ret.wid; y++)
        for (unsigned long z = 0; z < len; z++)
          MOD_ADD(&ret.data[x * ret.wid + y],
                  MOD_MUL(this->at(x, z), opn.at(z, y), m), m);
    return ret;
  }
  MATX &operator+=(const MATX &rhs) {
    *this = *this + rhs;
    return *this;
  }
  MATX &operator-=(const MATX &rhs) {
    *this = *this - rhs;
    return *this;
  }
  MATX &operator*=(const MATX &rhs) {
    *this = *this * rhs;
    return *this;
  }
  const MATX pow(const unsigned long p) const {
    MATX buff(*this), ret(this->hig, this->wid);
    ret.set_one();
    if (p > 0)
      for (unsigned long i = 1;; i <<= 1) {
        if (p & i) ret *= buff;
        buff *= buff;
        if (i > (p >> 1)) break;
      }
    return ret;
  }
  template <class T2>
  const MATX pow(const unsigned long p, const T2 m) const {
    MATX buff(*this), ret(this->hig, this->wid);
    ret.set_one();
    if (p > 0)
      for (unsigned long i = 1;; i <<= 1) {
        if (p & i) ret = ret.mul(buff, m);
        buff = buff.mul(buff, m);
        if (i > (p >> 1)) break;
      }
    return ret;
  }
  const T at(const unsigned long x, const unsigned long y) const {
    if (x >= this->hig || y >= this->wid) return 0;
    return this->data[x * wid + y];
  }
  void show() const {
    for (unsigned long x = 0; x < this->hig; x++) {
      for (unsigned long y = 0; y < this->wid; y++)
        cout << this->at(x, y) << " ";
      cout << endl;
    }
  }
  void set_one() {
    for (unsigned long x = 0; x < this->hig; x++)
      for (unsigned long y = 0; y < this->wid; y++)
        this->data[x * this->wid + y] = (x == y) ? 1 : 0;
  }
};
template <class T>
class complex_t {
 public:
  T r, i;
  complex_t(T x = 0.0, T y = 0.0) {
    this->r = x;
    this->i = y;
  }
  complex_t operator+(const complex_t &opn) const {
    return complex_t(this->r + opn.r, this->i + opn.i);
  }
  complex_t operator-(const complex_t &opn) const {
    return complex_t(this->r - opn.r, this->i - opn.i);
  }
  complex_t operator*(const complex_t &opn) const {
    return complex_t(this->r * opn.r - this->i * opn.i,
                     this->r * opn.i + this->i * opn.r);
  }
};
template <class T>
void fast_fourier_trans(complex_t<T> f[], const int len, const int is_dft) {
  for (int i = 1, j = len >> 1; i < len - 1; i++) {
    if (i < j) swap(f[i], f[j]);
    int k = len >> 1;
    while (j >= k) {
      j -= k;
      k >>= 1;
    }
    if (j < k) j += k;
  }
  for (int h = 2; h <= len; h <<= 1) {
    complex_t<T> wn(cos(is_dft ? (-2 * PI / h) : (2 * PI / h)),
                    sin(is_dft ? (-2 * PI / h) : (2 * PI / h)));
    for (int i = 0; i < len; i += h) {
      complex_t<T> wm(1.0, 0.0);
      for (int j = i; j < i + (h >> 1); j++) {
        complex_t<T> u = f[j];
        complex_t<T> t = wm * f[j + (h >> 1)];
        f[j] = u + t;
        f[j + (h >> 1)] = u - t;
        wm = wm * wn;
      }
    }
  }
  if (!is_dft) {
    for (int i = 0; i < len; i++) f[i].r /= len * 1.0;
  }
}
class MILLERRABIN {
 private:
  static const int prime_table[12];
  int witness(long long a, long long d, long long s, long long n) {
    long long r = MODL_POW(a, d, n);
    if (r == 1 || r == n - 1) return 0;
    for (int i = 0; i < s - 1; i++) {
      r = MODL_MUL(r, r, n);
      if (r == 1) return 1;
      if (r == n - 1) return 0;
    }
    return 1;
  }

 public:
  int test(const long long n) {
    if (n <= 2LL) return 0;
    long long p = n - 1LL, s = 0LL;
    while (!(p & 1)) {
      p >>= 1;
      s++;
    }
    for (int i = 0; i < 12 && this->prime_table[i] < n; i++) {
      if (witness(this->prime_table[i], p, s, n)) return 0;
    }
    return 1;
  }
};
const int MILLERRABIN::prime_table[12] = {2,  3,  5,  7,  11, 13,
                                          17, 19, 23, 29, 31, 37};
template <class T>
inline int fsign(const T x) {
  if (x > -eps && x < eps) return 0;
  return (x < 0.0) ? -1 : 1;
}
template <class T>
class point_t {
 public:
  T x, y;
  point_t() {
    this->x = 0.0;
    this->y = 0.0;
  }
  point_t(const T _x, const T _y) {
    this->x = _x;
    this->y = _y;
  }
  point_t operator-(const point_t &rhs) const {
    return point_t(this->x - rhs.x, this->y - rhs.y);
  }
  T operator^(const point_t &rhs) const {
    return this->x * rhs.y - this->y * rhs.x;
  }
  T operator*(const point_t &rhs) const {
    return this->x * rhs.x + this->y * rhs.y;
  }
  bool operator<(const point_t &rhs) const {
    if (fsign(this->y - rhs.y) != 0) return fsign(this->y - rhs.y) < 0;
    return fsign(this->x - rhs.x) < 0;
  }
  T cross(const point_t &p, const point_t &q) const {
    return (p - *this) ^ (q - *this);
  }
  void rotate(const double radian) {
    T x0 = x, y0 = y;
    T sinr = sin(radian);
    T cosr = cos(radian);
    x = x0 * cosr - y0 * sinr;
    y = x0 * sinr + y0 * cosr;
  }
  void rotate(const point_t &p, const double radian) {
    T x0 = x - p.x, y0 = y - p.y;
    T sinr = sin(radian);
    T cosr = cos(radian);
    x = x0 * cosr - y0 * sinr + p.x;
    y = x0 * sinr + y0 * cosr + p.y;
  }
  T dist2(const point_t &lhs, const point_t &rhs) const {
    return (lhs - rhs) * (lhs - rhs);
  }
  T dist2(const point_t &rhs) const { return (*this - rhs) * (*this - rhs); }
  T dist(const point_t &lhs, const point_t &rhs) const {
    return sqrt((lhs - rhs) * (lhs - rhs));
  }
  T dist(const point_t &rhs) const {
    return sqrt((*this - rhs) * (*this - rhs));
  }
};
template <class T>
class segment_t {
 public:
  point_t<T> p, q;
  segment_t() {
    this->p.x = this->p.y = 0.0;
    this->q.x = this->q.y = 0.0;
  }
  template <class T2>
  segment_t(const point_t<T2> &_p, const point_t<T2> &_q) {
    this->p.x = _p.x;
    this->p.y = _p.y;
    this->q.x = _q.x;
    this->q.y = _q.y;
  }
  segment_t(const T px, const T py, const T qx, const T qy) {
    this->p.x = px;
    this->p.y = py;
    this->q.x = qx;
    this->q.y = qy;
  }
  T length() const { return this->p.dist(this->q); }
  T length2() const { return this->p.dist2(this->q); }
  int contain(const point_t<T> &pnt, const int ignore_endpoint = 0) const {
    if (ignore_endpoint) {
      return fsign((this->p - pnt) ^ (this->q - pnt)) == 0 &&
             fsign((pnt.x - this->p.x) * (pnt.x - this->q.x)) < 0 &&
             fsign((pnt.y - this->p.y) * (pnt.y - this->q.y)) < 0;
    } else {
      return fsign((this->p - pnt) ^ (this->q - pnt)) == 0 &&
             fsign((pnt.x - this->p.x) * (pnt.x - this->q.x)) <= 0 &&
             fsign((pnt.y - this->p.y) * (pnt.y - this->q.y)) <= 0;
    }
  }
  int intersection(const segment_t &sa, const segment_t &sb,
                   const int ignore_endpoint = 0) const {
    if (!ignore_endpoint) {
      if (sa.contain(sb.p) || sa.contain(sb.q) || sb.contain(sa.p) ||
          sb.contain(sa.q))
        return 1;
    }
    return fsign(sa.p.cross(sa.q, sb.p)) * fsign(sa.p.cross(sa.q, sb.q)) < 0 &&
           fsign(sb.p.cross(sb.q, sa.p)) * fsign(sb.p.cross(sb.q, sa.q)) < 0;
  }
  int intersection(const segment_t &rhs, const int ignore_endpoint = 0) const {
    return this->intersection(*this, rhs, ignore_endpoint);
  }
};
template <class T>
static int compare_pas(const void *x, const void *y, void *z) {
  const point_t<T> *p1 = (point_t<T> *)x;
  const point_t<T> *p2 = (point_t<T> *)y;
  const point_t<T> *p0 = (point_t<T> *)z;
  int sgn = fsign(((*p1) - (*p0)) ^ ((*p2) - (*p0)));
  if (sgn != 0) return -sgn;
  return fsign(p0->dist2(*p1) - p0->dist2(*p2));
}
template <class T>
void polar_angle_sort(point_t<T> *pnts, const int n) {
  int p = 0;
  for (int i = 1; i < n; i++) {
    if (pnts[p] < pnts[i]) p = i;
  }
  swap(pnts[0], pnts[p]);
  qsort_r(pnts + 1, n - 1, sizeof(point_t<T>), compare_pas<T>, pnts);
}
template <class T>
void graham(point_t<T> *pnts, const int n, int *idx, int &m) {
  polar_angle_sort(pnts, n);
  m = 0;
  if (n < 3) return;
  idx[m++] = 0;
  idx[m++] = 1;
  for (int i = 2; i < n; i++) {
    while (m > 1 &&
           fsign(pnts[idx[m - 2]].cross(pnts[idx[m - 1]], pnts[i])) <= 0)
      m--;
    idx[m++] = i;
  }
}
int n, m;
int src[1100000], dst[1100000], eid;
int col[1100000], det[1100000];
long long ans;
inline int find(const int u) {
  if (col[u] != u) col[u] = find(col[u]);
  return col[u];
}
int main() {
  ios_base::sync_with_stdio(0);
  while (cin >> n >> m) {
    for (int i = 0; i < n; i++) col[i] = -1;
    eid = 0;
    for (int i = 0; i < m; i++) {
      int u, v;
      cin >> u >> v;
      u--;
      v--;
      col[u] = u;
      col[v] = v;
      if (u == v) continue;
      src[eid] = u;
      dst[eid] = v;
      eid++;
    }
    ans = m * 1LL * (m - 1LL);
    for (int i = 0; i < eid; i++) {
      int u = src[i];
      int v = dst[i];
      if (find(u) != find(v)) {
        col[find(v)] = find(u);
      }
    }
    int vrt = -1;
    for (int i = 0; i < n; i++) {
      if (!~col[i]) continue;
      if (!~vrt) {
        vrt = find(i);
      } else {
        if (vrt != find(i)) {
          ans = 0LL;
          break;
        }
      }
    }
    if (ans) {
      for (int i = 0; i < n; i++) det[i] = 0;
      for (int i = 0; i < eid; i++) {
        int u = src[i];
        int v = dst[i];
        det[u]++;
        det[v]++;
      }
      for (int i = 0; i < eid; i++) {
        int u = src[i];
        int v = dst[i];
        ans -= (eid - (det[u] - 1) - (det[v] - 1) - 1) * 1LL;
      }
      ans >>= 1;
    }
    cout << ans << endl;
  }
  return 0;
}

```