mod = 10 ** 9 + 7
def comb(m, r):
    if m < r:return 0
    if m < 0 or r < 0:return 0
    return fa[m] * fi[r] % mod * fi[m - r] % mod
n, m = map(int, input().split())
fa = [1] * (m + 1)
fi = [1] * (m + 1)
for i in range(1, m + 1):
    fa[i] = fa[i - 1] * i % mod
    fi[i] = pow(fa[i], mod - 2, mod)
ans = 0
for i in range(n, m + 1):
    ans += comb(i, n)
    ans %= mod
print(ans)