#include <bits/stdc++.h>
using namespace std;
using ll = long long;
ll power(const ll a, const ll n, const ll mod = -1)
{
    if (n == 0) {
        return 1;
    } else if (n % 2 == 1) {
        if (mod == -1) {
            return power(a, n - 1, mod) * a;
        } else {
            return (power(a, n - 1, mod) * a) % mod;
        }
    } else {
        const ll aa = power(a, n / 2, mod);
        if (mod == -1) {
            return aa * aa;
        } else {
            return (aa * aa) % mod;
        }
    }
}

class Modulo
{
public:
    Modulo(const int n, const ll mod = 1000000007LL) : m_size{n + 1}, m_mod{mod}  // mod should be prime
    {
        assert(n > 0);
        m_fact.resize(n + 1);
        m_inv.resize(n + 1);
        m_inv_fact.resize(n + 1);
        m_fact[0] = 1;
        m_inv[0] = 1;
        m_inv_fact[0] = 1;
        m_fact[1] = 1;
        m_inv[1] = 1;
        m_inv_fact[1] = 1;
        for (int i = 2; i <= n; i++) {
            m_fact[i] = (m_fact[i - 1] * static_cast<ll>(i)) % mod;
            m_inv[i] = ((mod - (mod / static_cast<ll>(i))) * m_inv[static_cast<unsigned int>(mod) % i]) % mod;
            m_inv_fact[i] = (m_inv_fact[i - 1] * m_inv[i]) % mod;
        }
    }

    ll factorial(const int n) const
    {
        assert(n < m_size);
        return m_fact[n];
    }

    ll inverse(const int n) const
    {
        assert(n < m_size);
        return m_inv[n];
    }

    ll inverseFactorial(const int n) const
    {
        assert(n < m_size);
        return m_inv_fact[n];
    }

    ll permutation(const int n, const int k) const
    {
        assert(n < m_size);
        assert(k <= n);
        return (m_fact[n] * m_inv_fact[n - k]) % m_mod;
    }

    ll combination(const int n, const int k) const
    {
        assert(n < m_size);
        assert(k <= n);
        return (((m_fact[n] * m_inv_fact[k]) % m_mod) * m_inv_fact[n - k]) % m_mod;
    }

    ll homogenious(const int n, const int k) const
    {
        if (n == 0 and k == 0) {
            return 1;
        }
        return combination(n + k - 1, k);
    }

private:
    const int m_size;
    const ll m_mod;
    vector<ll> m_fact;
    vector<ll> m_inv;
    vector<ll> m_inv_fact;
};

constexpr ll MOD = (ll)1e9 + 7LL;

int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    ll N, M;
    cin >> N >> M;
    if (N < M) {
        cout << 0 << endl;
    } else {
        Modulo mod(M);
        ll ans = power(M, N, MOD);
        for (int i = 1; i <= M; i++) {
            ans += (i % 2 == 1 ? MOD - ((mod.combination(M, i) * power(M - i, N, MOD)) % MOD) : (mod.combination(M, i) * power(M - i, N, MOD)) % MOD);
            ans %= MOD;
        }
        cout << ans << endl;
    }
    return 0;
}