#include<cstdio>
#include<cmath>
#include<algorithm>
#include<cstring>
#include<string>
#include<iostream>
#include<map>
#include<vector>
#include<set>
#include<queue>
using namespace std;

int a, b, c, d, e, k1, k2;

int main() 
{
	while (scanf("%d %d %d %d %d", &a, &b, &c, &d, &e) != EOF)
	{
		if (d < e) 
		{
			k1 = a * b * c - 2 * d * ((a - 2 * e) * (b - 2 * e) + (b - 2 * e) * (c - 2 * e) + (a - 2 * e) * (c - 2 * e));
		}
		else 
		{
			k1 = (a * b - (a - 2 * e) * (b - 2 * e)) * e * 2 + 4 * e * e * (c - 2 * e);
			k2 = (a - 2 * d) * (b - 2 * d) * (c - 2 * d);
			k1 = max(k1, k2);
		}
		printf("%d\n", k1);
	}
	return 0;
}