#include <bits/stdc++.h>
using namespace std;
template <class A, class B>
ostream& operator<<(ostream& out, const pair<A, B>& p) {
  return out << "(" << p.first << ", " << p.second << ")";
}
template <typename T, size_t N>
ostream& operator<<(ostream& out, const array<T, N>& a) {
  out << "[";
  bool first = true;
  for (auto& v : a) {
    out << (first ? "" : ", ");
    out << v;
    first = 0;
  }
  out << "]";
  return out;
}
template <typename T>
ostream& operator<<(ostream& out, const vector<T>& a) {
  out << "[";
  bool first = true;
  for (auto& v : a) {
    out << (first ? "" : ", ");
    out << v;
    first = 0;
  }
  out << "]";
  return out;
}
template <typename T, class Cmp>
ostream& operator<<(ostream& out, const set<T, Cmp>& a) {
  out << "{";
  bool first = true;
  for (auto& v : a) {
    out << (first ? "" : ", ");
    out << v;
    first = 0;
  }
  out << "}";
  return out;
}
template <typename U, typename T, class Cmp>
ostream& operator<<(ostream& out, const map<U, T, Cmp>& a) {
  out << "{";
  bool first = true;
  for (auto& p : a) {
    out << (first ? "" : ", ");
    out << p.first << ":" << p.second;
    first = 0;
  }
  out << "}";
  return out;
}
template <class T>
inline void YES(T condition) {
  if (condition)
    cout << "YES" << endl;
  else
    cout << "NO" << endl;
}
template <class T>
inline void Yes(T condition) {
  if (condition)
    cout << "Yes" << endl;
  else
    cout << "No" << endl;
}
template <class T>
T gcd(T a, T b) {
  if (a && b) {
    return gcd(min(a, b), max(a, b) % min(a, b));
  } else {
    return a;
  }
}
template <class T>
T lcm(T a, T b) {
  return a / gcd(a, b) * b;
}
long long qpow(long long a, long long b, int MOD) {
  if (b == 0) return 1;
  long long res = 1;
  while (b) {
    if (b & 1) res = (res * a) % MOD;
    a = (a * a) % MOD;
    b >>= 1;
  }
  return res;
}
const int MOD = 1e9 + 7;
const int maxn = 2e6;
int fac[maxn + 5];
int invfac[maxn + 5];
void init() {
  fac[0] = 1;
  for (int i = 1; i <= maxn; i++) fac[i] = 1LL * fac[i - 1] * i % MOD;
  invfac[maxn] = (int)(qpow(fac[maxn], MOD - 2, MOD));
  for (int i = maxn - 1; i >= 0; i--)
    invfac[i] = 1LL * invfac[i + 1] * (i + 1) % MOD;
}
int C(int n, int k) {
  assert(0 <= k && n >= k);
  int tmp = (int)(1LL * invfac[k] * invfac[n - k] % MOD);
  return (int)(1LL * fac[n] * tmp % MOD);
}
int main() {
  cin.tie(nullptr);
  ios::sync_with_stdio(false);
  int n, k;
  cin >> n >> k;
  init();
  long long ans = 0;
  int flag = 1;
  for (int i = 0; i <= n; i++, flag = -flag) {
    long long tmp =
        (qpow(k, n - i, MOD) * qpow(k - 1, i, MOD) % MOD - qpow(k - 1, n, MOD));
    tmp = (tmp % MOD + MOD) % MOD;
    ans = (ans + flag * C(n, i) * qpow(tmp, n, MOD)) % MOD;
  }
  ans = (ans % MOD + MOD) % MOD;
  cout << ans << '\n';
  return 0;
}
