#include <stdio.h>
#include <string.h>
#include <algorithm>
#include <iostream>
#include <math.h>
#include <assert.h>
#include <vector>
#include <queue>
#include <string>
#include <map>
#include <set>
 
using namespace std;
typedef long long ll;
typedef unsigned int uint;
typedef unsigned long long ull;
static const double EPS = 1e-9;
static const double PI = acos(-1.0);
 
#define REP(i, n) for (int i = 0; i < (int)(n); i++)
#define FOR(i, s, n) for (int i = (s); i < (int)(n); i++)
#define FOREQ(i, s, n) for (int i = (s); i <= (int)(n); i++)
#define FORIT(it, c) for (__typeof((c).begin())it = (c).begin(); it != (c).end(); it++)
#define MEMSET(v, h) memset((v), h, sizeof(v))
 
 
struct Edge {
  bool ban;
  char src;
  char dest;
  int flag;
  int cost;
  Edge(int src, int dest, int flag, int cost) : ban(0), src(src), dest(dest), flag(flag), cost(cost) {;}
  Edge(int ban, int src, int dest, int flag, int cost) : ban(ban), src(src), dest(dest), flag(flag), cost(cost) {;}
  bool operator<(const Edge &rhs) const {
    return cost > rhs.cost;
  }
};
typedef vector<Edge> Edges;
typedef vector<Edges> Graph;
typedef vector<int> Array;
typedef vector<Array> Matrix;
 
void PrintMatrix(const Matrix &matrix) {
  for (int y = 0; y < (int)matrix.size(); y++) {
    for (int x = 0; x < (int)matrix[y].size(); x++) {
      printf("%d ", matrix[y][x]);
    }
    puts("");
  }
}
 
const ll INF = 1e+7;
int dist[15][1 << 22];
int lm[20];
int lf[20];
int ln;
int n;
int m;
int indexs[20];
 
int mapto[20][20];
Graph lg[20];
Graph g;
 
void Clear(int n, int m) {
  REP(i, n) {
    memset(dist[i], 0x0f, sizeof(int) * (1 << m));
  }
}
 
void TSP(const Graph &g, int s, int ini, int ef, int end) {
  queue<Edge> que;
  que.push(Edge(s, s, ini, 0));
  dist[s][ini] = 0;
  while (!que.empty()) {
    Edge e = que.front();
    que.pop();
    int from = e.dest;
    if (dist[from][e.flag] != e.cost) { continue; }
    if (from == end && e.flag == ef) { break; }
    FORIT(it, g[from]) {
      if (e.flag & it->flag) { continue; }
      int nfrom = from;
      int nto = it->dest;
      int nflag = e.flag | it->flag;
      int ncost = e.cost + it->cost;
      if (dist[nto][nflag] <= ncost) { continue; }
      dist[nto][nflag] = ncost;
      que.push(Edge(nfrom, nto, nflag, ncost));
    }
  }
}
 
int START;
int TSP2(int ban, int from, int flag) {
  int ret = INF;
  FORIT(it, g[from]) {
    if (flag & it->flag) { continue; }
    int nban = (it->flag >= (1 << n)) ? 1 : 0;
    int to = it->dest;
    if (ban && nban) { continue; }
    int nflag = flag | it->flag;
    if (to == START && nflag == (1 << m) - 1) { ret = it->cost; break; }
    if (to == START) { continue; }
    if (!nban && dist[to][nflag] != 0x0f0f0f0f) {
      ret = min(ret, dist[to][nflag] + it->cost);
    } else {
      ret = min(ret, TSP2(nban, to, nflag) + it->cost);
    }
  }
  if (!ban) {
    dist[from][flag] = ret;
  }
  return ret;
}
 
void CalcMoveCost3(int c, int s, int e, int n1, int n2, int n3) {
  int bit = (1 << lm[c]) - 1;
  bit ^= 7;
  bit |= (1 << (lm[c] + s));
  if (n1) { bit |= 1; }
  if (n2) { bit |= 2; }
  if (n3) { bit |= 4; }
  int cost = dist[e][bit];
 
  int offset = mapto[c][0];
  int from = mapto[c][s];
  int to = mapto[c][e];
  int flag = (1 << m) | (n1 << (offset + 0)) | (n2 << (offset + 1)) | (n3 << (offset + 2));
  if (cost >= INF) { return; }
  g[from].push_back(Edge(from, to, flag, cost));
}
 
void CalcMoveCost4(int c, int s, int e, int n1, int n2, int n3, int n4) {
  int bit = (1 <<lm[c]) - 1;
  bit ^= 15;
  bit |= (1 << (lm[c] + s));
  if (n1) { bit |= 1; }
  if (n2) { bit |= 2; }
  if (n3) { bit |= 4; }
  if (n4) { bit |= 8; }
  int cost = dist[e][bit];
 
  int offset = mapto[c][0];
  int from = mapto[c][s];
  int to = mapto[c][e];
  int flag = (3 << m) | (n1 << (offset + 0)) | (n2 << (offset + 1)) | (n3 << (offset + 2)) | (n4 << (offset + 3));
  if (cost >= INF) { return; }
  g[from].push_back(Edge(from, to, flag, cost));
}
 
void CalcMoveCost4Divide(int c, int s1, int e1, int s2, int e2) {
  int left = (1 << (lm[c] + s1)) | (1 << e1);
  int right = (1 << (lm[c] + s2)) | (1 << e2);
  assert((left & right) == 0);
  int mask = ((1 << lm[c]) - 1) ^ 15;
  int cost = INF;
  FOREQ(i, 0, mask) {
    if ((mask | i) != mask) { continue; }
    int div  = mask ^ i;
    cost = min(cost, dist[e1][left | i] + dist[e2][right | div]);
  }
  int offset = mapto[c][0];
  int f1 = mapto[c][s1];
  int t1 = mapto[c][e1];
  int f2 = mapto[c][s2];
  int t2 = mapto[c][e2];
  int flag1 = (1 << m) | (1 << (offset + e1));
  int flag2 = (1 << m) | (1 << (offset + s1));
  int flag3 = (2 << m) | (1 << (offset + e2));
  int flag4 = (2 << m) | (1 << (offset + s2));
  if (cost >= INF) { return; }
  g[f1].push_back(Edge(f1, t1, flag1, cost));
  g[t1].push_back(Edge(t1, f1, flag2, cost));
  g[f2].push_back(Edge(f2, t2, flag3, 0));
  g[t2].push_back(Edge(t2, f2, flag4, 0));
 
  //cout << f1 << " " << t1 << " " << flag1 << " " << f2 << " " << t2 << " " << flag3 << endl;
  //cout << cost << endl;
}
 
void MakeInnerEdge(int c) {
  Clear(lm[c], lm[c] + lf[c]);
  REP(i, lf[c]) {
    TSP(lg[c], i, 1 << (lm[c] + i), -1, -1);
  }
  indexs[c] = m;
  if (lf[c] == 2) {
    int from = mapto[c][0];
    int to = mapto[c][1];
    int cost = dist[1][(((1 << lm[c]) - 1) ^ 1) | (1 << lm[c])];
    g[from].push_back(Edge(from, to, (1 << m) | (1 << to), cost));
    g[to].push_back(Edge(to, from, (1 << m) | (1 << from), cost));
    m++;
  } else if (lf[c] == 3) {
    REP(s, 3) {
      REP(e, 3) {
        if (s == e) { continue; }
        REP(n1, 2) {
         if (s == 0 && n1) { continue; }
         if (e == 0 && !n1) { continue; }
          REP(n2, 2) {
            if (s == 1 && n2) { continue; }
            if (e == 1 && !n2) { continue; }
            REP(n3, 2) {
              if (s == 2 && n3) { continue; }
              if (e == 2 && !n3) { continue; }
              CalcMoveCost3(c, s, e, n1, n2, n3);
            }
          }
        }
      }
    }
    m++;
  } else if (lf[c] == 4) {
    // a -> some -> b -> other -> c -> rest -> d
    REP(s, 4) {
      REP(e, 4) {
        if (s == e) { continue; }
        REP(n1, 2) {
          if (s == 0 && n1) { continue; }
          if (e == 0 && !n1) { continue; }
          REP(n2, 2) {
            if (s == 1 && n2) { continue; }
            if (e == 1 && !n2) { continue; }
            REP(n3, 2) {
              if (s == 2 && n3) { continue; }
              if (e == 2 && !n3) { continue; }
              REP(n4, 2) {
                if (s == 3 && n4) { continue; }
                if (e == 3 && !n4) { continue; }
                CalcMoveCost4(c, s, e, n1, n2, n3, n4);
              }
            }
          }
        }
      }
    }
 
    // a -> some -> b, c -> rest -> d
    CalcMoveCost4Divide(c, 0, 1, 2, 3);
    CalcMoveCost4Divide(c, 0, 2, 1, 3);
    CalcMoveCost4Divide(c, 0, 3, 1, 2);
    m += 2;
  } else {
    assert(false);
  }
}
 
int main() {
  int k;
  while (scanf("%d %d", &ln, &k) > 0) {
    int minValue = 5;
    int minIndex = -1;
    g.clear();
    REP(i, 20) { lg[i].clear(); }
    MEMSET(mapto, 0xdf);
    n = 0;
    REP(i, ln) {
      scanf("%d", &lm[i]);
      lg[i] = Graph(lm[i]);
    }
    REP(i, ln) {
      scanf("%d", &lf[i]);
      if (lf[i] < minValue) {
        minValue = lf[i];
        minIndex = i;
      }
      REP(j, lf[i]) {
        mapto[i][j] = n++;
      }
    }
    g = Graph(n);
    REP(i, k) {
      int fl, fs, tl, ts, c;
      scanf("%d %d %d %d %d", &fl, &fs, &tl, &ts, &c);
      fl--; fs--; tl--; ts--;
      if (mapto[fl][fs] >= 0 && mapto[tl][ts] >= 0) {
        int f = mapto[fl][fs];
        int t = mapto[tl][ts];
        g[f].push_back(Edge(f, t, 1 << t, c));
        g[t].push_back(Edge(t, f, 1 << f, c));
      }
      if (fl == tl) {
        lg[fl][fs].push_back(Edge(fs, ts, 1 << ts, c));
        lg[fl][ts].push_back(Edge(ts, fs, 1 << fs, c));
      }
    }
    m = n;
    int ans = INF;
    if (ln == 1) {
      Clear(lm[0], lm[0]);
      TSP(lg[0], 0, 0, (1 << lm[0]) - 1, 0);
      ans = dist[0][(1 << lm[0]) - 1];
      if (lm[0] == 1) { ans = 0; }
    } else {
      REP(i, ln) {
        if (lm[i] == lf[i]) { continue; }
        if (lf[i] == 1) { goto ANS; }
        MakeInnerEdge(i);
      }
      assert(m <= 22);
      // if (m >= 22) {
      //   Clear(n, m);
      //   srand(time(NULL));
      //   START = mapto[minIndex][rand() % minValue];
      //   ans = min(ans, TSP2(g, 0, START, 0));
      // } else {
        REP(i, max(minValue - 1, 1)) {
          Clear(n, m);
          START = mapto[minIndex][i];
          dist[START][(1 << m) - 1] = 0;
          ans = min(ans, TSP2(0, START, 0));
        }
      //}
    }
ANS:
    if (ans < INF) {
      printf("%d\n", ans);
    } else {
      puts("-1");
    }
  }
}
### Prompt

In cpp, your task is to solve the following problem:

Kita_masa is planning a trip around the world. This world has N countries and the country i has M_i cities. Kita_masa wants to visit every city exactly once, and return back to the starting city.

In this world, people can travel only by airplane. There are two kinds of airlines: domestic and international lines. Since international airports require special facilities such as customs and passport control, only a few cities in each country have international airports.

You are given a list of all flight routes in this world and prices for each route. Now it's time to calculate the cheapest route for Kita_masa's world trip!



Input

The first line contains two integers N and K, which represent the number of countries and the number of flight routes, respectively. The second line contains N integers, and the i-th integer M_i represents the number of cities in the country i. The third line contains N integers too, and the i-th integer F_i represents the number of international airports in the country i. Each of the following K lines contains five integers [Country 1] [City 1] [Country 2] [City 2] [Price]. This means that, there is a bi-directional flight route between the [City 1] in [Country 1] and the [City 2] in [Country 2], and its price is [Price].

Note that cities in each country are numbered from 1, and the cities whose city number is smaller or equal to F_i have international airports. That is, if there is a flight route between the city c_1 in the country n_1 and the city c_2 in the country n_2 with n_1 \neq n_2, it must be c_1 \leq F_{n_1} and c_2 \leq F_{n_2}. You can assume that there's no flight route which departs from one city and flies back to the same city, and that at most one flight route exists in this world for each pair of cities.

The following constraints hold for each dataset:

* 1 \leq N \leq 15
* 1 \leq M_i \leq 15
* 1 \leq F_i \leq 4
* sum(F_i) \leq 15
* 1 \leq Price \leq 10,000

Output

Print a line that contains a single integer representing the minimum price to make a world trip.

If such a trip is impossible, print -1 instead.

Examples

Input

4 6
1 1 1 1
1 1 1 1
1 1 2 1 1
1 1 3 1 2
1 1 4 1 1
2 1 3 1 1
2 1 4 1 2
3 1 4 1 1


Output

4


Input

2 16
4 4
2 2
1 1 1 2 1
1 1 1 3 2
1 1 1 4 1
1 2 1 3 1
1 2 1 4 2
1 3 1 4 1
2 1 2 2 1
2 1 2 3 2
2 1 2 4 1
2 2 2 3 1
2 2 2 4 2
2 3 2 4 1
1 1 2 1 1
1 1 2 2 2
1 2 2 1 2
1 2 2 2 1


Output

8


Input

2 2
2 1
1 1
1 1 1 2 1
1 1 2 1 1


Output

-1

### Response

```cpp
#include <stdio.h>
#include <string.h>
#include <algorithm>
#include <iostream>
#include <math.h>
#include <assert.h>
#include <vector>
#include <queue>
#include <string>
#include <map>
#include <set>
 
using namespace std;
typedef long long ll;
typedef unsigned int uint;
typedef unsigned long long ull;
static const double EPS = 1e-9;
static const double PI = acos(-1.0);
 
#define REP(i, n) for (int i = 0; i < (int)(n); i++)
#define FOR(i, s, n) for (int i = (s); i < (int)(n); i++)
#define FOREQ(i, s, n) for (int i = (s); i <= (int)(n); i++)
#define FORIT(it, c) for (__typeof((c).begin())it = (c).begin(); it != (c).end(); it++)
#define MEMSET(v, h) memset((v), h, sizeof(v))
 
 
struct Edge {
  bool ban;
  char src;
  char dest;
  int flag;
  int cost;
  Edge(int src, int dest, int flag, int cost) : ban(0), src(src), dest(dest), flag(flag), cost(cost) {;}
  Edge(int ban, int src, int dest, int flag, int cost) : ban(ban), src(src), dest(dest), flag(flag), cost(cost) {;}
  bool operator<(const Edge &rhs) const {
    return cost > rhs.cost;
  }
};
typedef vector<Edge> Edges;
typedef vector<Edges> Graph;
typedef vector<int> Array;
typedef vector<Array> Matrix;
 
void PrintMatrix(const Matrix &matrix) {
  for (int y = 0; y < (int)matrix.size(); y++) {
    for (int x = 0; x < (int)matrix[y].size(); x++) {
      printf("%d ", matrix[y][x]);
    }
    puts("");
  }
}
 
const ll INF = 1e+7;
int dist[15][1 << 22];
int lm[20];
int lf[20];
int ln;
int n;
int m;
int indexs[20];
 
int mapto[20][20];
Graph lg[20];
Graph g;
 
void Clear(int n, int m) {
  REP(i, n) {
    memset(dist[i], 0x0f, sizeof(int) * (1 << m));
  }
}
 
void TSP(const Graph &g, int s, int ini, int ef, int end) {
  queue<Edge> que;
  que.push(Edge(s, s, ini, 0));
  dist[s][ini] = 0;
  while (!que.empty()) {
    Edge e = que.front();
    que.pop();
    int from = e.dest;
    if (dist[from][e.flag] != e.cost) { continue; }
    if (from == end && e.flag == ef) { break; }
    FORIT(it, g[from]) {
      if (e.flag & it->flag) { continue; }
      int nfrom = from;
      int nto = it->dest;
      int nflag = e.flag | it->flag;
      int ncost = e.cost + it->cost;
      if (dist[nto][nflag] <= ncost) { continue; }
      dist[nto][nflag] = ncost;
      que.push(Edge(nfrom, nto, nflag, ncost));
    }
  }
}
 
int START;
int TSP2(int ban, int from, int flag) {
  int ret = INF;
  FORIT(it, g[from]) {
    if (flag & it->flag) { continue; }
    int nban = (it->flag >= (1 << n)) ? 1 : 0;
    int to = it->dest;
    if (ban && nban) { continue; }
    int nflag = flag | it->flag;
    if (to == START && nflag == (1 << m) - 1) { ret = it->cost; break; }
    if (to == START) { continue; }
    if (!nban && dist[to][nflag] != 0x0f0f0f0f) {
      ret = min(ret, dist[to][nflag] + it->cost);
    } else {
      ret = min(ret, TSP2(nban, to, nflag) + it->cost);
    }
  }
  if (!ban) {
    dist[from][flag] = ret;
  }
  return ret;
}
 
void CalcMoveCost3(int c, int s, int e, int n1, int n2, int n3) {
  int bit = (1 << lm[c]) - 1;
  bit ^= 7;
  bit |= (1 << (lm[c] + s));
  if (n1) { bit |= 1; }
  if (n2) { bit |= 2; }
  if (n3) { bit |= 4; }
  int cost = dist[e][bit];
 
  int offset = mapto[c][0];
  int from = mapto[c][s];
  int to = mapto[c][e];
  int flag = (1 << m) | (n1 << (offset + 0)) | (n2 << (offset + 1)) | (n3 << (offset + 2));
  if (cost >= INF) { return; }
  g[from].push_back(Edge(from, to, flag, cost));
}
 
void CalcMoveCost4(int c, int s, int e, int n1, int n2, int n3, int n4) {
  int bit = (1 <<lm[c]) - 1;
  bit ^= 15;
  bit |= (1 << (lm[c] + s));
  if (n1) { bit |= 1; }
  if (n2) { bit |= 2; }
  if (n3) { bit |= 4; }
  if (n4) { bit |= 8; }
  int cost = dist[e][bit];
 
  int offset = mapto[c][0];
  int from = mapto[c][s];
  int to = mapto[c][e];
  int flag = (3 << m) | (n1 << (offset + 0)) | (n2 << (offset + 1)) | (n3 << (offset + 2)) | (n4 << (offset + 3));
  if (cost >= INF) { return; }
  g[from].push_back(Edge(from, to, flag, cost));
}
 
void CalcMoveCost4Divide(int c, int s1, int e1, int s2, int e2) {
  int left = (1 << (lm[c] + s1)) | (1 << e1);
  int right = (1 << (lm[c] + s2)) | (1 << e2);
  assert((left & right) == 0);
  int mask = ((1 << lm[c]) - 1) ^ 15;
  int cost = INF;
  FOREQ(i, 0, mask) {
    if ((mask | i) != mask) { continue; }
    int div  = mask ^ i;
    cost = min(cost, dist[e1][left | i] + dist[e2][right | div]);
  }
  int offset = mapto[c][0];
  int f1 = mapto[c][s1];
  int t1 = mapto[c][e1];
  int f2 = mapto[c][s2];
  int t2 = mapto[c][e2];
  int flag1 = (1 << m) | (1 << (offset + e1));
  int flag2 = (1 << m) | (1 << (offset + s1));
  int flag3 = (2 << m) | (1 << (offset + e2));
  int flag4 = (2 << m) | (1 << (offset + s2));
  if (cost >= INF) { return; }
  g[f1].push_back(Edge(f1, t1, flag1, cost));
  g[t1].push_back(Edge(t1, f1, flag2, cost));
  g[f2].push_back(Edge(f2, t2, flag3, 0));
  g[t2].push_back(Edge(t2, f2, flag4, 0));
 
  //cout << f1 << " " << t1 << " " << flag1 << " " << f2 << " " << t2 << " " << flag3 << endl;
  //cout << cost << endl;
}
 
void MakeInnerEdge(int c) {
  Clear(lm[c], lm[c] + lf[c]);
  REP(i, lf[c]) {
    TSP(lg[c], i, 1 << (lm[c] + i), -1, -1);
  }
  indexs[c] = m;
  if (lf[c] == 2) {
    int from = mapto[c][0];
    int to = mapto[c][1];
    int cost = dist[1][(((1 << lm[c]) - 1) ^ 1) | (1 << lm[c])];
    g[from].push_back(Edge(from, to, (1 << m) | (1 << to), cost));
    g[to].push_back(Edge(to, from, (1 << m) | (1 << from), cost));
    m++;
  } else if (lf[c] == 3) {
    REP(s, 3) {
      REP(e, 3) {
        if (s == e) { continue; }
        REP(n1, 2) {
         if (s == 0 && n1) { continue; }
         if (e == 0 && !n1) { continue; }
          REP(n2, 2) {
            if (s == 1 && n2) { continue; }
            if (e == 1 && !n2) { continue; }
            REP(n3, 2) {
              if (s == 2 && n3) { continue; }
              if (e == 2 && !n3) { continue; }
              CalcMoveCost3(c, s, e, n1, n2, n3);
            }
          }
        }
      }
    }
    m++;
  } else if (lf[c] == 4) {
    // a -> some -> b -> other -> c -> rest -> d
    REP(s, 4) {
      REP(e, 4) {
        if (s == e) { continue; }
        REP(n1, 2) {
          if (s == 0 && n1) { continue; }
          if (e == 0 && !n1) { continue; }
          REP(n2, 2) {
            if (s == 1 && n2) { continue; }
            if (e == 1 && !n2) { continue; }
            REP(n3, 2) {
              if (s == 2 && n3) { continue; }
              if (e == 2 && !n3) { continue; }
              REP(n4, 2) {
                if (s == 3 && n4) { continue; }
                if (e == 3 && !n4) { continue; }
                CalcMoveCost4(c, s, e, n1, n2, n3, n4);
              }
            }
          }
        }
      }
    }
 
    // a -> some -> b, c -> rest -> d
    CalcMoveCost4Divide(c, 0, 1, 2, 3);
    CalcMoveCost4Divide(c, 0, 2, 1, 3);
    CalcMoveCost4Divide(c, 0, 3, 1, 2);
    m += 2;
  } else {
    assert(false);
  }
}
 
int main() {
  int k;
  while (scanf("%d %d", &ln, &k) > 0) {
    int minValue = 5;
    int minIndex = -1;
    g.clear();
    REP(i, 20) { lg[i].clear(); }
    MEMSET(mapto, 0xdf);
    n = 0;
    REP(i, ln) {
      scanf("%d", &lm[i]);
      lg[i] = Graph(lm[i]);
    }
    REP(i, ln) {
      scanf("%d", &lf[i]);
      if (lf[i] < minValue) {
        minValue = lf[i];
        minIndex = i;
      }
      REP(j, lf[i]) {
        mapto[i][j] = n++;
      }
    }
    g = Graph(n);
    REP(i, k) {
      int fl, fs, tl, ts, c;
      scanf("%d %d %d %d %d", &fl, &fs, &tl, &ts, &c);
      fl--; fs--; tl--; ts--;
      if (mapto[fl][fs] >= 0 && mapto[tl][ts] >= 0) {
        int f = mapto[fl][fs];
        int t = mapto[tl][ts];
        g[f].push_back(Edge(f, t, 1 << t, c));
        g[t].push_back(Edge(t, f, 1 << f, c));
      }
      if (fl == tl) {
        lg[fl][fs].push_back(Edge(fs, ts, 1 << ts, c));
        lg[fl][ts].push_back(Edge(ts, fs, 1 << fs, c));
      }
    }
    m = n;
    int ans = INF;
    if (ln == 1) {
      Clear(lm[0], lm[0]);
      TSP(lg[0], 0, 0, (1 << lm[0]) - 1, 0);
      ans = dist[0][(1 << lm[0]) - 1];
      if (lm[0] == 1) { ans = 0; }
    } else {
      REP(i, ln) {
        if (lm[i] == lf[i]) { continue; }
        if (lf[i] == 1) { goto ANS; }
        MakeInnerEdge(i);
      }
      assert(m <= 22);
      // if (m >= 22) {
      //   Clear(n, m);
      //   srand(time(NULL));
      //   START = mapto[minIndex][rand() % minValue];
      //   ans = min(ans, TSP2(g, 0, START, 0));
      // } else {
        REP(i, max(minValue - 1, 1)) {
          Clear(n, m);
          START = mapto[minIndex][i];
          dist[START][(1 << m) - 1] = 0;
          ans = min(ans, TSP2(0, START, 0));
        }
      //}
    }
ANS:
    if (ans < INF) {
      printf("%d\n", ans);
    } else {
      puts("-1");
    }
  }
}
```