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

// ここからはけんちょんさんのブログからコピペ
// https://drken1215.hatenablog.com/entry/2018/06/08/210000

const int MAX = 510000;
const int MOD = 1000000007;
long long fac[MAX], finv[MAX], inv[MAX];

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

long long COM(int n, int k){
    if (n < k) return 0;
    if (n < 0 || k < 0) return 0;
    return fac[n] * (finv[k] * finv[n - k] % MOD) % MOD;
}

// ここまでコピペ

int main() {
    long long n, m;
    cin >> n >> m;
    COMinit();
    long long ans = 0;
    for(long long i = n; i <= m; ++i) {
        ans += COM(i, n);
        ans %= MOD;
    }
    cout << ans << endl;
    return 0;
}