#include <iostream>
#include <iomanip>
using namespace std;
int main() {
double x,y,z,x1,y1,z1,n;
cin >> x >> y >> z >> x1 >> y1 >> z1 >> n;
double sum = x1/x + y1/y + z1/z;
cout << fixed << setprecision(n) << sum << endl;
}
#include <iostream>
#include <iomanip>
using namespace std;
int main() {
double x,y,z,x1,y1,z1,n;
cin >> x >> y >> z >> x1 >> y1 >> z1 >> n;
double sum = x1/x + y1/y + z1/z;
cout << fixed << setprecision(n) << sum << endl;
}