#include <iostream>

using namespace std;

int main()
{
	int a,b,c,d,m,e = 0,f = 0,sum = 0;
	cin >> a >> b >> c >> d >> m;
	e = 5 * c;
	f = 20 * d;
	if (e >= m) {
		sum += (e + f);
		sum -= (b - d) * 20;
	}
	else {
		sum += e;
		sum -= (b - d) * 20;
	}
	if (sum <= 0) {
		sum = 0;
	}
	cout << sum;
	return 0;
 }