# include <bits/stdc++.h>
using namespace std;
typedef long long ll;

const ll mod = 1e9 + 7;
const int N = 100010;
ll n, m, res;
ll fac[N], inv[N], finv[N];
constexpr ll INF=1e16;

void init()
{
	fac[0] = fac[1] = inv[0] = inv[1] = finv[0] = finv[1] = 1;
	for (int i = 1; i < N; i++) fac[i] = fac[i - 1] * i % mod;
	for (int i = 2; i < N; i++) inv[i] = (mod - mod / i) * inv[mod % i] % mod;
	for (int i = 2; i < N; i++) finv[i] = finv[i - 1] * inv[i] % mod;
}

ll C(ll x, ll y)
{
	if (x < y) return 0;
	return fac[x] * finv[x - y] % mod * finv[y] % mod;
}

ll ksm(ll x, ll y)
{
	ll res;
	res = 1;
	while (y)
	{
		res = (y & 1) ? res * x % mod : res;
		x = x * x % mod;
		y >>= 1;
	}
	return res;
}

int main()
{
	init();
	scanf("%lld%lld", &n, &m);
	if (n < m) printf("0\n"), exit(0);
	res = 0;
	for (int i = 0; i <= m; i++)
	{
		if ((m - i) & 1) res = (res - C(m, i) * ksm(i, n) % mod + mod) % mod;
		else res = (res + C(m, i) * ksm(i, n) % mod) % mod;
	}
	printf("%lld\n", res);
	return 0;
}