#include <bits/stdc++.h>
using namespace std;
const long long MOD = 1000000007;
long long modpow(long long a, long long b){
  long long ans = 1;
  while (b > 0){
    if (b % 2 == 1){
      ans *= a;
      ans %= MOD;
    }
    a *= a;
    a %= MOD;
    b /= 2;
  }
  return ans;
}
int main(){
  int N;
  long long K;
  cin >> N >> K;
  K %= MOD;
  long long tmp = (long long) K * (K + 1) / 2 + K;
  tmp %= MOD;
  long long tmp2 = modpow(tmp, N);
  long long tmp3 = (long long) K * (K + 1) / 2;
  tmp3 %= MOD;
  long long tmp4 = modpow(tmp3, N);
  cout << (tmp2 - tmp4 + MOD) % MOD << endl;
}