mod = 10 ** 9 + 7
div2 = pow(2, mod - 2, mod)


class Combination:
    """
    SIZEが10**6程度以下の二項係数を何回も呼び出したいときに使う
    使い方:
    comb = Combination(SIZE, MOD)
    comb(10, 3) => 120
    """

    def __init__(self, N, MOD=10 ** 9 + 7):
        self.MOD = MOD
        self.__make_factorial_list(N)

    def __call__(self, n, k):
        if k < 0 or k > n:
            return 0
        res = self.fact[n] * self.inv[k] % self.MOD
        res = res * self.inv[n - k] % self.MOD
        return res

    def nPk(self, n, k):
        if k < 0 or k > n:
            return 0
        return self.fact[n] * self.inv[n - k] % self.MOD

    def nHk(self, n, k):
        if k == 0:
            return 1
        return self.__call__(n + k - 1, k)

    def __make_factorial_list(self, N):
        self.fact = [1] * (N + 1)
        self.inv = [1] * (N + 1)
        MOD = self.MOD
        for i in range(1, N + 1):
            self.fact[i] = (self.fact[i - 1] * i) % MOD
        self.inv[N] = pow(self.fact[N], MOD - 2, MOD)
        for i in range(N, 0, -1):
            self.inv[i - 1] = (self.inv[i] * i) % MOD
        return


def main():
    H, W = map(int, input().split())
    comb = Combination(10 ** 6 + 5, mod)

    ans = 0

    for i in range(H + 1):
        a = pow(2, H * W - i * W, mod)
        if i % 2 == 1:
            a = mod - a
        r = - pow(div2, H - i, mod)
        n = W + 1

        tot = a * pow(1 + r, W, mod)
        tot = tot * comb(H, i) % mod
        ans = (ans + tot) % mod

    return ans


print(main())