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

long long power( long long x, int n, int m )
{
	long long res = 1;
	while( n > 0 ) {
		if( n %  2 ) res = res * x % m;
		x = x * x % m;
		n /= 2;
	}
	return res;
}

int main()
{
	long long N, M;
	cin >> N >> M;

	const int MOD = 1000000000 + 7;
	vector<long long> fac( M + 1 );
	vector<long long> ifac( M + 1 );
	fac[0] = 1;
	ifac[0] = power( 1, MOD - 2, MOD );
	for( int i = 1; i <= M; i++ ) {
		fac[i] = fac[i - 1] * i;
		fac[i] %= MOD;
		ifac[i] = power( fac[i], MOD - 2, MOD );
	}
	long long ans = 0;
	for( int i = N; i <= M; i++ ) {
		ans += fac[i] * ifac[N] % MOD * ifac[i - N] % MOD;
		ans %= MOD;
	}

	cout << ans << endl;
}