#include <iostream>
#include <vector>
using namespace std;
int main(){
    int a, b, c, d, n;
    cin>>a>>b>>c>>d>>n;
    long long answer;
    if (a>c){
        if (b>d){
            if (n/(a-c)>n/(b-d)){
                answer=((n-b-1)/(b-d)+2)*(a+b+c+d)-c-d;
            }else{
                answer=((n-a-1)/(a-c)+2)*(a+b+c+d)-b-c-d;
            }
        }else{
            if (n/(a-c)>n/(d-b)){
                answer=((n-1)/(d-b)+1)*(a+b+c+d);
            }else{
                answer=((n-a-1)/(a-c)+2)*(a+b+c+d)-b-c-d;
            }
        }
    }else{
        if (b>d){
            if (n/(c-a)>n/(b-d)){
                answer=((n-b-1)/(b-d)+2)*(a+b+c+d)-c-d;
            }else{
                answer=((n-1)/(c-a)+1)*(a+b+c+d)-d;
            }
        }else{
            if (n/(a-c)>n/(d-b)){
                answer=((n-1)/(d-b)+1)*(a+b+c+d);
            }else{
                answer=((n-1)/(c-a)+1)*(a+b+c+d)-d;
            }
        }
    }
    cout<<answer<<endl;
}