func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 510;   const int mod = 1e9 + 7;   long long mi1[N], mi[N], C[N][N], dp[N][N];   int main() {     int n, m;     scanf( %d%d , &n, &m);     mi[0] = mi1[0] = 1;     for (int i = 1; i <= n; i++) {       mi[i] = mi[i - 1] * m % mod;       mi1[i] = mi1[i - 1] * (m - 1) % mod;     }     for (int i = 0; i <= n; i++) {       C[i][0] = 1;       for (int j = 1; j <= i; j++)         C[i][j] = (C[i - 1][j] + C[i - 1][j - 1]) % mod;     }     for (int j = 1; j <= n; j++) dp[1][j] = C[n][j] * mi1[n - j] % mod;     for (int i = 2; i <= n; i++) {       for (int j = 0; j <= n; j++) {         for (int k = 0; k <= j; k++) {           long long V;           V = (dp[i - 1][k] % mod * C[n - k][j - k] % mod * mi1[n - j] % mod *                mi[k] % mod) %               mod;           dp[i][j] = (dp[i][j] + V) % mod;           if (j == k)             dp[i][j] = (dp[i][j] - mi1[n] * dp[i - 1][k] % mod + mod) % mod;         }       }     }     printf( %lld n , dp[n][n]);   }   