/* -*- coding: utf-8 -*-
 *
 * 1126.cc:  No.1126 SUM - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int MOD = 1000000007;

/* typedef */

typedef long long ll;

/* global variables */

/* subroutines */

int powmod(int a, int n) {  // a^n % MOD
  int pm = 1;
  while (n > 0) {
    if (n & 1) pm = (ll)pm * a % MOD;
    a = (ll)a * a % MOD;
    n >>= 1;
  }
  return pm;
}

/* main */

int main() {
  int n, m;
  scanf("%d%d", &n, &m);

  int sum = 1, c = 1;
  for (int i = n + 1; i <= m; i++) {
    c = (ll)c * i % MOD * powmod(i - n, MOD - 2) % MOD;
    sum = (sum + c) % MOD;
  }

  printf("%d\n", sum);
  return 0;
}