#include<bits/stdc++.h>
#define int long long 
using namespace std;
int ans,a,b,c,d,m;
signed main(){
	scanf("%lld%lld%lld%lld%lld",&a,&b,&c,&d,&m);
	if(c*5<=m){
		ans+=c*5;
		ans+=(b-d)*20;
	}
	else{
		ans+=c*5;
		ans+=d*20-(b-d)*20;
	}
	if(ans>0) printf("%lld",ans);
	else printf("0");
	return 0;
}