import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
import numpy as np

MOD = 10 ** 9 + 7


def cumprod(A, MOD=MOD):
    L = len(A)
    Lsq = int(L**.5 + 1)
    A = np.resize(A, Lsq**2).reshape(Lsq, Lsq)
    for n in range(1, Lsq):
        A[:, n] *= A[:, n - 1]
        A[:, n] %= MOD
    for n in range(1, Lsq):
        A[n] *= A[n - 1, -1]
        A[n] %= MOD
    return A.ravel()[:L]


def make_fact(U, MOD=MOD):
    x = np.arange(U, dtype=np.int64)
    x[0] = 1
    fact = cumprod(x, MOD)
    x = np.arange(U, 0, -1, dtype=np.int64)
    x[0] = pow(int(fact[-1]), MOD - 2, MOD)
    fact_inv = cumprod(x, MOD)[::-1]
    fact.flags.writeable = False
    fact_inv.flags.writeable = False
    return fact, fact_inv


fact, fact_inv = make_fact(10 ** 5 + 10)
N, M = map(int, read().split())


def power(A, n):
    if n == 1:
        return A
    B = power(A, n // 2)
    B = B * B % MOD
    return A * B % MOD if n & 1 else B


comb = fact[M] * fact_inv[: M + 1] % MOD * fact_inv[: M + 1][::-1] % MOD
power = power(np.arange(M + 1, dtype=np.int64)[::-1], N)
x = comb * power % MOD
x[1::2] *= (-1)
print(x.sum() % MOD)