func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long p = 1000000007LL;   long long power(long long x, long long n) {     long long ret = 1LL;     while (n > 0LL) {       if (n & 1LL) ret = ret * x % p;       x = x * x % p;       n >>= 1LL;     }     return ret;   }   long long n, m;   long long dp;   int main() {     cin >> n >> m;     dp = 1;     for (long long i = 1LL; i <= n; i++)       dp = (dp * (m * 2LL - 1LL) + power(m, i - 1LL)) % p;     cout << dp << endl;   }   