"""

A,B,C
B*C,A*C,A*B

A*A*B*C,

A*B*C の 2^K 乗

"""

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

K = int(input())

mod = 10**9+7
print ( pow(A*B*C, pow(2,K,mod-1) ,mod) )