A, B, C = map(int,input().split())
K = int(input())
x = A * B * C

#for _ in range(K):
#    x = x * x % 1000000007
    #print(A * B * C % 1000000007)

k = pow(2, K, 10 ** 9 + 6)


print(pow(x, k, 10 ** 9 + 7))