#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using mint = atcoder::modint1000000007;

int main(){
    int n, m;
    cin >> n >> m;
    vector<mint> fact(m + 1), inv(m + 1);
    fact[0] = 1;
    for(int i = 1; i <= m; i++)fact[i] = i * fact[i - 1];
    inv[m] = 1 / fact[m];
    for(int i = m; i >= 1; i--)inv[i - 1] = i * inv[i];
    mint ans;
    for(int i = n; i <= m; i++){
        ans += fact[i] * inv[i - n] * inv[n];
    }
    cout << ans.val() << '\n';
}