The presidential election is coming in Bearland next year! Everybody is so excited about this!

So far, there are three candidates, Alice, Bob, and Charlie. 

There are n citizens in Bearland. The election result will determine the life of all citizens of Bearland for many years. Because of this great responsibility, each of n citizens will choose one of six orders of preference between Alice, Bob and Charlie uniformly at random, independently from other voters.

The government of Bearland has devised a function to help determine the outcome of the election given the voters preferences. More specifically, the function is <image> (takes n boolean numbers and returns a boolean number). The function also obeys the following property: f(1 - x1, 1 - x2, ..., 1 - xn) = 1 - f(x1, x2, ..., xn).

Three rounds will be run between each pair of candidates: Alice and Bob, Bob and Charlie, Charlie and Alice. In each round, xi will be equal to 1, if i-th citizen prefers the first candidate to second in this round, and 0 otherwise. After this, y = f(x1, x2, ..., xn) will be calculated. If y = 1, the first candidate will be declared as winner in this round. If y = 0, the second will be the winner, respectively.

Define the probability that there is a candidate who won two rounds as p. p·6n is always an integer. Print the value of this integer modulo 109 + 7 = 1 000 000 007.

Input

The first line contains one integer n (1 ≤ n ≤ 20).

The next line contains a string of length 2n of zeros and ones, representing function f. Let bk(x) the k-th bit in binary representation of x, i-th (0-based) digit of this string shows the return value of f(b1(i), b2(i), ..., bn(i)).

It is guaranteed that f(1 - x1, 1 - x2, ..., 1 - xn) = 1 - f(x1, x2, ..., xn) for any values of x1, x2, ldots, xn.

Output

Output one integer — answer to the problem.

Examples

Input

3
01010101


Output

216


Input

3
01101001


Output

168

Note

In first sample, result is always fully determined by the first voter. In other words, f(x1, x2, x3) = x1. Thus, any no matter what happens, there will be a candidate who won two rounds (more specifically, the candidate who is at the top of voter 1's preference list), so p = 1, and we print 1·63 = 216.
#include <bits/stdc++.h>
#pragma GCC optimize("O3", "unroll-loops")
using namespace std;
namespace {
const int MOD107 = 1000000007;
const int MOD998 = 998244353;
using ll = long long;
using ull = unsigned long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
template <class T>
using minheap = priority_queue<T, vector<T>, greater<T>>;
template <class T>
using maxheap = priority_queue<T, vector<T>, less<T>>;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
struct Modular {
 private:
  long long MODVALUE = 0;
  long long val = 0;
  Modular initModular(long long val) const { return Modular(val, MODVALUE); }
  inline void validate() const {}
  inline void validate(const Modular& other) const {}

 public:
  explicit operator long long() const { return val; }
  template <class T>
  Modular& operator=(const T& other) {
    val = (other % MODVALUE + MODVALUE) % MODVALUE;
    return *this;
  }
  template <class T>
  void setMod(const T& MOD) {
    MODVALUE = MOD;
  }
  Modular& operator+=(const Modular& other) {
    validate(other);
    val += other.val;
    if (val >= MODVALUE) val -= MODVALUE;
    return *this;
  }
  Modular operator+(const Modular& other) const {
    Modular tmp = *this;
    return tmp += other;
  }
  template <class T>
  Modular& operator+=(const T& other) {
    return *this += initModular(other);
  }
  template <class T>
  Modular operator+(const T& other) const {
    return *this + initModular(other);
  }
  template <class T>
  friend Modular operator+(const T& other, const Modular& m) {
    return m.initModular(other) + m;
  }
  Modular& operator++() { return *this += 1; }
  Modular operator++(int) {
    Modular tmp = *this;
    ++*this;
    return tmp;
  }
  Modular operator-() const { return initModular(-val); }
  Modular& operator-=(const Modular& other) {
    validate(other);
    val -= other.val;
    if (val < 0) val += MODVALUE;
    return *this;
  }
  Modular operator-(const Modular& other) const {
    Modular tmp = *this;
    return tmp -= other;
  }
  template <class T>
  Modular& operator-=(const T& other) {
    return *this -= initModular(other);
  }
  template <class T>
  Modular operator-(const T& other) const {
    return *this - initModular(other);
  }
  template <class T>
  friend Modular operator-(const T& other, const Modular& m) {
    return m.initModular(other) - m;
  }
  Modular& operator--() { return *this -= 1; }
  Modular operator--(int) {
    Modular tmp = *this;
    --*this;
    return tmp;
  }
  Modular& operator*=(const Modular& other) {
    validate(other);
    val *= other.val;
    val %= MODVALUE;
    if (val < 0) val += MODVALUE;
    return *this;
  }
  Modular operator*(const Modular& other) const {
    Modular tmp = *this;
    return tmp *= other;
  }
  template <class T>
  Modular& operator*=(const T& other) {
    return *this *= initModular(other);
  }
  template <class T>
  Modular operator*(const T& other) const {
    return *this * initModular(other);
  }
  template <class T>
  friend Modular operator*(const T& other, const Modular& m) {
    return m.initModular(other) * m;
  }
  Modular pow(long long power) const {
    Modular m = *this, ans = initModular(1);
    while (power) {
      if (power & 1) ans *= m;
      m *= m;
      power >>= 1;
    }
    return ans;
  }
  Modular pow(const Modular& other) const { return pow(other.val); }
  Modular inv() const { return pow(MODVALUE - 2); }
  Modular& operator/=(const Modular& other) {
    val *= other.inv().val;
    val %= MODVALUE;
    if (val < 0) val += MODVALUE;
    return *this;
  }
  Modular operator/(const Modular& other) const {
    Modular tmp = *this;
    return tmp /= other;
  }
  template <class T>
  Modular& operator/=(const T& other) {
    return *this /= initModular(other);
  }
  template <class T>
  Modular operator/(const T& other) const {
    return *this / initModular(other);
  }
  template <class T>
  friend Modular operator/(const T& other, const Modular& m) {
    return m.initModular(other) / m;
  }
  friend istream& operator>>(istream& in, Modular& m) {
    in >> m.val;
    m.val %= m.MODVALUE;
    if (m.val < 0) m.val += m.MODVALUE;
    return in;
  }
  friend ostream& operator<<(ostream& out, const Modular& m) {
    return out << m.val;
  }
  Modular() {
    val = 0;
    MODVALUE = 0;
  }
  Modular(long long val, long long MOD)
      : MODVALUE(MOD), val((val % MOD + MOD) % MOD) {}
};
using Mint = Modular;
inline ll binpow(ll b, ll p, ll mod) {
  b %= mod;
  ll ans = 1;
  for (; p > 0; p >>= 1) {
    if (p & 1) {
      ans *= b;
      ans %= mod;
    }
    b *= b;
    b %= mod;
  }
  return ans;
}
inline ll max(ll a, int b) { return (a > b ? a : b); }
inline ll max(int a, ll b) { return (a > b ? a : b); }
inline ll min(ll a, int b) { return (a < b ? a : b); }
inline ll min(int a, ll b) { return (a < b ? a : b); }
template <class T>
inline bool chkmin(T& x, const T& y) {
  return x > y ? x = y, 1 : 0;
}
template <class T>
inline bool chkmax(T& x, const T& y) {
  return x < y ? x = y, 1 : 0;
}
}  // namespace
namespace IO {
template <class T>
inline void _R(T& x) {
  cin >> x;
}
template <class T1, class T2>
inline void _R(pair<T1, T2>& x) {
  _R(x.first);
  _R(x.second);
}
template <class T>
inline void _R(vector<T>& x) {
  for (auto& i : x) _R(i);
}
template <class T>
inline void _R(deque<T>& x) {
  for (auto& i : x) _R(i);
}
inline void R() {}
template <class T1, class... T2>
inline void R(T1& x, T2&... y) {
  _R(x);
  R(y...);
}
template <class T>
inline void _W(const T& x);
template <class T1, class T2>
inline void _W(const pair<T1, T2>& p);
template <class... T>
inline void _W(const vector<T...>& x);
template <class... T>
inline void _W(const deque<T...>& x);
template <class... T>
inline void _W(const forward_list<T...>& x);
template <class... T>
inline void _W(const list<T...>& x);
template <class... T>
inline void _W(const set<T...>& x);
template <class... T>
inline void _W(const multiset<T...>& x);
template <class... T>
inline void _W(const unordered_set<T...>& x);
template <class... T>
inline void _W(const unordered_multiset<T...>& x);
template <class... T>
inline void _W(const map<T...>& x);
template <class... T>
inline void _W(const multimap<T...>& x);
template <class... T>
inline void _W(const unordered_map<T...>& x);
template <class... T>
inline void _W(const unordered_multimap<T...>& x);
template <class Container>
inline void printContainer(const Container& x) {
  bool isFirst = 1;
  for (auto i : x) {
    if (!isFirst) cout << ' ';
    isFirst = 0;
    _W(i);
  }
}
template <class T>
inline void _W(const T& x) {
  cout << x;
}
template <class T1, class T2>
inline void _W(const pair<T1, T2>& p) {
  _W(p.first);
  _W(' ');
  _W(p.second);
}
template <class... T>
inline void _W(const vector<T...>& x) {
  printContainer(x);
}
template <class... T>
inline void _W(const deque<T...>& x) {
  printContainer(x);
}
template <class... T>
inline void _W(const forward_list<T...>& x) {
  printContainer(x);
}
template <class... T>
inline void _W(const list<T...>& x) {
  printContainer(x);
}
template <class... T>
inline void _W(const set<T...>& x) {
  printContainer(x);
}
template <class... T>
inline void _W(const multiset<T...>& x) {
  printContainer(x);
}
template <class... T>
inline void _W(const unordered_set<T...>& x) {
  printContainer(x);
}
template <class... T>
inline void _W(const unordered_multiset<T...>& x) {
  printContainer(x);
}
template <class... T>
inline void _W(const map<T...>& x) {
  printContainer(x);
}
template <class... T>
inline void _W(const multimap<T...>& x) {
  printContainer(x);
}
template <class... T>
inline void _W(const unordered_map<T...>& x) {
  printContainer(x);
}
template <class... T>
inline void _W(const unordered_multimap<T...>& x) {
  printContainer(x);
}
inline void W() { cout << '\n'; }
template <class T>
inline void W(const T& x) {
  _W(x);
  W();
}
template <class T1, class... T2>
inline void W(const T1& x, const T2&... y) {
  _W(x);
  _W(' ');
  W(y...);
}
}  // namespace IO
using namespace IO;
namespace outputFormat {
inline string Case(int tc) { return "Case #" + to_string(tc) + ':'; }
inline string YN(bool b) { return b ? "Yes" : "No"; }
}  // namespace outputFormat
using namespace outputFormat;
namespace std {
template <class T1, class T2>
struct hash<pair<T1, T2>> {
  std::size_t operator()(pair<T1, T2> _) const {
    return hash<T1>{}(_.first) ^ hash<T2>{}(_.second);
  }
};
}  // namespace std
int main() {
  int n;
  R(n);
  int N = 1 << n;
  string s;
  R(s);
  vector<ll> v(N);
  for (int i = 0; i < N; i++) v[i] = s[i] - '0';
  auto fwht = [&](vector<ll>& a, bool inv) {
    for (int i = 1, j = 0; i < N; i++) {
      int bit = N >> 1;
      for (; j & bit; bit >>= 1) j ^= bit;
      j ^= bit;
      if (i < j) swap(a[i], a[j]);
    }
    for (int len = 2; len <= N; len <<= 1) {
      for (int i = 0; i < N; i += len) {
        for (int j = 0; j < len / 2; j++) {
          ll u = a[i + j];
          ll v = a[i + j + len / 2];
          a[i + j] = u + v;
          a[i + j + len / 2] = u - v;
        }
      }
    }
    if (inv) {
      for (int i = 0; i < N; i++) a[i] /= N;
    }
  };
  fwht(v, false);
  for (int i = 0; i < N; i++) v[i] *= v[i];
  fwht(v, true);
  vector<ll> d(n + 1);
  for (int i = 0; i < N; i++) d[__builtin_popcount(i)] += v[i];
  vector<ll> mul(n + 1);
  mul[n] = 1;
  for (int i = n - 1; i >= 0; i--) mul[i] = mul[i + 1] << 1;
  ll ans = 0;
  for (int i = 0; i <= n; i++) ans += d[i] * mul[i];
  ans *= 3;
  W(ans % MOD107);
  return 0;
}
static auto __init__ = []() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout << fixed << setprecision(10);
  return 42;
}();
