#include<stdio.h>
 int main(void){
	 int a,b,c,d,e,v,v1,v2;
	while (scanf("%d%d%d%d%d",&a,&b,&c,&d,&e)!=EOF){
		if(e>d){
	 v=a*b*c-2*(c-2*e)*(a-2*e)*d-2*(b-2*e)*(c-2*e)*d-2*(a-2*e)*(b-2*e)*d;
		}
		else
		{v1=8*e*e*e+4*(a-2*e)*e*e+4*(b-2*e)*e*e+4*(c-2*e)*e*e;
		v2=(a-2*d)*(b-2*d)*(c-2*d);
		if(v1>=v2) v=v1;
		else v=v2;
		}
	 printf("%d\n",v);
	
 }
	return 0;
 }