func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 24;   int n, m, a[N][N], f[1 << 20];   char str[N][N];   void work() {     int i, j, k, x;     scanf( %d%d , &n, &m);     for (i = 0; i < n; ++i) scanf( %s , str[i]);     for (i = 0; i < n; ++i)       for (j = 0; j < m; ++j) scanf( %d , &a[i][j]);     for (i = 1; i < 1 << n; ++i) {       x = __builtin_ctz(i & -i);       f[i] = 1 << 30;       for (j = 0; j < m; ++j) {         f[i] = min(f[i], f[i ^ (1 << x)] + a[x][j]);         int sum = 0, mx = 0, mask = 0;         for (k = 0; k < n; ++k) {           if (str[k][j] == str[x][j]) {             sum += a[k][j];             mx = max(mx, a[k][j]);             mask |= 1 << k;           }         }         f[i] = min(f[i], f[i & (i ^ mask)] + sum - mx);       }     }     cout << f[(1 << n) - 1] << endl;   }   int main() {     work();     return 0;   }   