func_code_string: #include <bits/stdc++.h>   using namespace std;   long long a, b, mod, sumz, sumy, sum, last, first, kol, z;   long long run(long long x, long long step) {     long long res = 1;     while (step) {       if (step & 1) res = (res * x) % mod;       x = x * x % mod;       step >>= 1;     }     return res % mod;   }   int main() {     cin >> a >> b;     mod = 1000 * 1000 * 1000 + 7;     sumz = (a * b) % mod;     sumz = (sumz * (b - 1)) % mod;     sumz = (sumz * run(2, mod - 2)) % mod;     sumy = (a * (a + 1)) % mod;     sumy = (sumy * b) % mod;     sumy = (sumy * (b - 1)) % mod;     sumy = (sumy * run(4, mod - 2)) % mod;     sum = ((b * sumy) % mod + sumz) % mod;     cout << sum << endl;     return 0;   }   