#include <iostream>
#include <fstream>
using namespace std;

int main()
{   ifstream in("iepure.in");
    ofstream out("iepure.out");
    int t , x , y , z , a , b , c , n , m ;
in>>t>>x>>y>>z>>a>>b>>c>>n;

//cout<<"Dati numarul de seturi: T=";
   // cin>>t;

while(n>=3)
{
    m=z*a+y*b+x*c;
    n--;
    x=y;
    y=z;
    z=m;
    }
    //t=t-1;
        out<<m;


}