#include<iostream>
using namespace std;
int main(){
    int w,a,b,c,d,m;
    cin>>a>>b>>c>>d>>m;
    if(c*5>m){
        w=c*5+d*20-(b-d)*20;
    }
    else{
        w=c*5-(b-d)*20;
    }
    if(w<0){
        cout<<0;
        return 0;
    }

    cout<<w;
    return 0;
}