import java.util.*; public class Main { static final int MOD = 1000000007; public static void main (String[] args) { Scanner sc = new Scanner(System.in); int n = sc.nextInt(); int m = sc.nextInt(); Combination cmb = new Combination(m + 1); long ans = 0; for (int i = n; i <= m; i++) { ans += cmb.getComb(i, n); ans %= MOD; } System.out.println(ans); } } class Combination { static final int MOD = 1000000007; long[] fac; long[] finv; long[] inv; public Combination (int size) { fac = new long [size]; finv = new long [size]; inv = new long [size]; fac[0] = 1; fac[1] = 1; finv[0] = 1; finv[1] = 1; inv[1] = 1; for (int i = 2; i < size; 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; } } public long getComb(int n, int k) { if (n < k || n < 0 || k < 0) { return 0; } return fac[n] * (finv[k] * finv[n - k] % MOD) % MOD; } }