#include <bits/stdc++.h>
using namespace std;
const long long MOD = 1000000007;
int main(){
  int K;
  long long N;
  cin >> K >> N;
  assert(K >= 3 && N >= 4);
  vector<long long> dp000(K + 1, 0);
  vector<long long> dp001(K + 1, 0);
  vector<long long> dp011(K + 1, 0);
  vector<long long> dp012(K + 1, 0);
  vector<long long> dp111(K + 1, 0);
  vector<long long> dp112(K + 1, 0);
  vector<long long> dp123(K + 1, 0);
  dp000[0] = N;
  dp001[0] = N - 1;
  dp011[0] = N - 1;
  dp012[0] = max(N - 2, (long long) 0);
  dp111[0] = N - 1;
  dp112[0] = max(N - 2, (long long) 0);
  dp123[0] = max(N - 3, (long long) 0);
  for (int i = 0; i < K; i++){
    dp000[i + 1] = N * dp001[i] % MOD * dp001[i] % MOD * dp001[i] % MOD;
    dp001[i + 1] += (N - 1) * dp001[i] % MOD * dp012[i] % MOD * dp012[i] % MOD;
    dp001[i + 1] += dp001[i] * dp011[i] % MOD * dp011[i] % MOD;
    dp001[i + 1] %= MOD;
    dp011[i + 1] += (N - 1) * dp012[i] % MOD * dp012[i] % MOD * dp112[i] % MOD;
    dp011[i + 1] += dp011[i] * dp011[i] % MOD * dp111[i] % MOD;
    dp011[i + 1] %= MOD;
    if (N >= 2){
      dp012[i + 1] += (N - 2) * dp012[i] % MOD * dp012[i] % MOD * dp123[i] % MOD;
      dp012[i + 1] += 2 * dp011[i] % MOD * dp012[i] % MOD * dp112[i] % MOD;
      dp012[i + 1] %= MOD;
    }
    dp111[i + 1] += (N - 1) * dp112[i] % MOD * dp112[i] % MOD * dp112[i] % MOD;
    dp111[i + 1] += dp111[i] * dp111[i] % MOD * dp111[i] % MOD;
    dp111[i + 1] %= MOD;
    if (N >= 2){
      dp112[i + 1] += (N - 2) * dp112[i] % MOD * dp123[i] % MOD * dp123[i] % MOD;
      dp112[i + 1] += dp112[i] % MOD * dp112[i] % MOD * dp111[i] % MOD;
      dp112[i + 1] += dp112[i] % MOD * dp112[i] % MOD * dp112[i] % MOD;
      dp112[i + 1] %= MOD;
    }
    if (N >= 3){
      dp123[i + 1] += (N - 3) * dp123[i] % MOD * dp123[i] % MOD * dp123[i] % MOD;
      dp123[i + 1] += 3 * dp112[i] % MOD * dp123[i] % MOD * dp123[i] % MOD;
      dp123[i + 1] %= MOD;
    }
  }
  cout << dp000[K] << endl;
}