N, M = map(int, input().split())
MOD = 10 ** 9 + 7
modinv = lambda a, mod=MOD: pow(a, -1, mod)

tmp = 1
ans = 1
for i in range(N + 1, M + 1):
    tmp = tmp * i * modinv(i - N) % MOD
    ans = (ans + tmp) % MOD
print(ans)