#include<iostream>
#include<cstdio>
using namespace std;


int max(int a,int b)
{
	return a>b?a:b;
}
int main()
{
	int a,b,c,d,e,ans;
	while(cin >> a >> b >> c >> d >> e)
	{
		if (d<e)
			ans=a*b*c-2*d*((a-2*e)*(b-2*e)+(b-2*e)*(c-2*e)+(a-2*e)*(c-2*e));
		else
			ans=max(a*b*c-2*e*((a-2*e)*(b-2*e)+(b-2*e)*(c-2*e)+(a-2*e)*(c-2*e))-(a-2*e)*(b-2*e)*(c-2*e),(a-2*d)*(b-2*d)*(c-2*d));
		cout << ans << endl;
	}
}