#include <iostream>
#include<fstream>


using namespace std;

int iepuri(int x,int y,int z,int a,int b,int c,long n){
int p;
if(n==3)
     return a*z+b*y+c*x;
p=a*z+b*y+c*x;
x=y;
y=z;
z=p;
n--;
return iepuri(x,y,z,a,b,c,n);


}


int main()
{
     ifstream fin("iepuri.in");
     ofstream fout("iepuri.out");
     int x,y,z,a,b,c,t;
     long n;
     fin>>t;
     while(t){
          fin>>x>>y>>z>>a>>b>>c>>n;
          fout<<iepuri(x,y,z,a,b,c,n)<<endl;
          t--;
     }


    return 0;
}