#include <bits/stdc++.h>
using namespace std;
const double pi = acos(-1.0);
const double eps = 1e-10;
const long long MOD = 1e9 + 7;
long long farm(int a, int b) {
  long long i, j, k;
  long long k1a = (1 + a);
  k1a *= a;
  k1a /= 2;
  k1a %= MOD;
  long long j1b = (1 + b - 1);
  j1b *= b - 1;
  j1b /= 2;
  j1b %= MOD;
  j1b *= k1a;
  j1b %= MOD;
  long long ans = 1;
  long long ta = (1LL + (long long)a) * a / 2;
  ta %= MOD;
  ta = ta * b + a;
  ta %= MOD;
  long long tb = (long long)b * (b - 1) / 2;
  tb %= MOD;
  ans = ta * tb;
  ans %= MOD;
  return ans % MOD;
}
int main() {
  int a, b;
  scanf("%d%d", &a, &b);
  printf("%I64d\n", farm(a, b));
  return 0;
}
