lapla-cogito/AGC019A

## AGC019A
#include <iostream>
#include <algorithm>
using namespace std;
int main(){
  long long int a,b,c,d,e;
  cin>>a>>b>>c>>d>>e;
  long long ans=min(e*4*a,min(e*2*b,e*c));
  cout<<min(e/2*d+e%2*ans/e,ans)<<endl;
}
	#include <iostream>
	#include <algorithm>
	using namespace std;
	int main(){
	long long int a,b,c,d,e;
	cin>>a>>b>>c>>d>>e;
	long long ans=min(e4a,min(e2b,e*c));
	cout<<min(e/2d+e%2ans/e,ans)<<endl;
	}