MOD = 10 ** 9 + 7
fac = [1] * (10 ** 5 + 1)
for i in range(len(fac) - 1):
    fac[i + 1] = fac[i] * (i + 1) % MOD


def comb(n, k):
    return fac[n] * pow(fac[n - k] * fac[k], MOD - 2, MOD) % MOD


n, m = map(int, input().split())
ans = 0
for i in range(n, m + 1):
    ans += comb(i, n)
print(ans % MOD)