func_code_string: #include <bits/stdc++.h>   using namespace std;   int n, m;   long long a, b;   int main() {     scanf( %d %d , &n, &m);     a = 0, b = 1;     for (int i = (1); i <= (n); i++) {       long long c, d;       d = 2 * m * b - a;       a = m * b + (m - 1) * a;       b = d;       a %= 1000000007;       b %= 1000000007;     }     printf( %lld n , (b + 1000000007) % 1000000007);     return 0;   }   