#include<iostream>
#include<vector>
#include<string>
#include<set>
#include<map>
#include<ios>
#include<iomanip> 
#include<cmath>
#include<limits>
#include<algorithm>

using namespace std;

long long MOD = 1000000007;
int main(){
    long long a,b,c,k;
    cin >> a >> b >> c;
    cin >> k;

    long long tmp_a,tmp_b,tmp_c,tmp_multi;
    long long digit = pow(2.0,k);
    digit %= MOD-1;
    tmp_a = (long long)pow(a,digit);
    tmp_b = (long long)pow(b,digit);
    tmp_c = (long long)pow(c,digit);
    tmp_multi = tmp_a * tmp_b * tmp_c;
    cout << (int)tmp_multi%MOD << endl;
    return 0;
}