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

long long n, m, ans = 0, w = 1, z = 1, y;
const long long M = 1e9 + 7;

long long powm(long long a, long long b) {
	long long u = 1, v = a;

	while (b > 0) {
		if (b & 1)
			u = u * v % M;

		b >>= 1;
		v = v * v % M;
	}

	return u;
}

int main()
{
	cin >> n >> m;

	if (m > n)
		cout << 0 << endl;
	else {
		if (m % 2 == 1)
			y = -1;
		else
			y = 1;

		for (int i = 1; i <= m; i++) {
			w = w * (m - i + 1) % M;
			z = z * i % M;
			y *= -1;

			if (i == m)
				ans = (ans + powm(i, n)) % M;
			else
				ans = (ans + M + w * powm(z, M - 2) % M * powm(i, n) % M * y) % M;			
		}

		cout << ans << endl;
	}
}