MOD = 10**9 + 7
A, B, C = map(int, input().split())
K = int(input())

p0 = A % MOD
p0 = p0 * (B % MOD) % MOD
p0 = p0 * (C % MOD) % MOD

if p0 == 0:
    print(0)
else:
    exponent = pow(2, K, MOD - 1)
    result = pow(p0, exponent, MOD)
    print(result)