func_code_string: #include <bits/stdc++.h>   using namespace std;   using pil = pair<long long, long long>;   using pii = pair<long long, long long>;   using pid = pair<double, double>;   long long mod = 1e9 + 7;   long long power(long long a, long long n) {     long long res = 1;     while (n) {       if (n % 2) res = (res * a) % mod;       a = (a * a) % mod;       n /= 2;     }     return res;   }   void solve() {     long long a, b;     cin >> a >> b;     long long B = (b * (b - 1) / 2) % mod;     long long A = ((a * (a + 1) / 2) % mod) * b + a;     A %= mod;     long long ans = (A * B) % mod;     cout << ans << endl;   }   int32_t main() {     long long t = 1;     while (t--) {       solve();     }   }   