#include <bits/stdc++.h>
#define ll long long
using namespace std;

ll a,b,c,d,m;

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