// yukicoder: No.391 CODING WAR
// 2019.5.8 bal4u

#include <stdio.h>

typedef long long ll;
#define MOD 1000000007
#define MAX 100000

int fact[MAX+2], inv[MAX+2], factinv[MAX+2];

int comb(int n, int k)
{
    if (n < 0 || k < 0 || n < k) return 0;
	if (k == 0) return 1;
    return ((((ll)fact[n] * factinv[k]) % MOD) * factinv[n-k]) % MOD;
}

int modpow(int x, long long p)
{
	int r = 1;
	while (p) {
		if (p & 1) r = (ll)r * x % MOD;
		x = (ll)x * x % MOD;
		p >>= 1;
	}
	return r;
}

int main()
{
	int M, i, a;
	ll N, ans;

	fact[0] = 1; for (i = 1; i <= MAX; i++)
		fact[i] = ((ll)fact[i-1]*i) % MOD;
	inv[1] = 1; for (i = 2; i <= MAX; i++)
		inv[i] = (MOD + (-(MOD/i)*(ll)inv[MOD % i]) % MOD) % MOD;
	factinv[0] = 1; for (i = 1; i <= MAX; i++)
		factinv[i] = ((ll)factinv[i-1]*inv[i]) % MOD;

	scanf("%lld%d", &N, &M);
	if (N < M) ans = 0;
	else {
		int sign = (M & 1);
		ans = 0; for (i = 1; i <= M; i++) {
			a = ((ll)modpow(i, N) * comb(M, i)) % MOD;
			if (sign) ans += a; else ans -= a;
			sign = !sign;
		}
	}
	ans %= MOD;
	if (ans < MOD) ans += MOD;
    printf("%d\n", (int)ans);
	return 0;
}