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

int main()
{
	int a,b,c,d,e;
	while(cin >> a >> b >> c >> d >> e) {
		if (d>=e) {
			int a1 = (a-2*d)*(b-2*d)*(c-2*d);
			int a2 = (a*c-(a-2*e)*(c-2*e))*e*2+(b-2*e)*e*e*4;
			if(a1>a2)
				cout << a1 << endl;
			else
				cout << a2 << endl;
		}
		else
			cout << a*b*c - 2*(a-2*e)*(c-2*e)*d
				-2*(a-2*e)*(b-2*e)*d
				-2*(b-2*e)*(c-2*e)*d
				<< endl;
	}
}