#include<iostream>
#include<cstdlib>
#include<cmath>
#include<cstring>
#include<iomanip>
#include<algorithm>
using namespace std;
int main()
{
	int a,b,c,d,e;
	while(cin>>a>>b>>c>>d>>e)
	{
		if(d>=e)
		{
			int v1=e*e*a;
			int v2=(b-2*e)*e*e;
			int v3=(c-2*e)*e*e;
			cout<<max(v1*4+v2*4+v3*4,(b-2*d)*(a-2*d)*(c-2*d))<<endl;
		}else
		{
			int v0=a*b*c;
			int vv1=(a-2*e)*(c-2*e)*d*2;
			int vv2=(b-2*e)*(c-2*e)*d*2;
			int vv3=(a-2*e)*(b-2*e)*d*2;
			cout<<v0-vv1-vv2-vv3<<endl;
		}
	}
}