using System;
using System.Collections.Generic;
using static System.Console;
using System.Linq;

class yuki302
{
    static long[] NList => ReadLine().Split().Select(long.Parse).ToArray();
    static void Main()
    {
        var c = NList;
        var k = long.Parse(ReadLine());
        var key = 1000000007;
        WriteLine(Exp((c[0] * c[1] % key) * c[2] % key, Exp(2, k, key - 1), key));
    }
    static long Exp(long n, long k, int keyNum)
    {
        if (k == 0) return 1;
        if (k == 1) return n % keyNum;
        var half = Exp(n, k / 2, keyNum);
        var result = (half * half) % keyNum;
        return ((k % 2) == 0) ? result : ((result * n) % keyNum);
    }
}