#include<stdio.h>
#include<math.h>

int main(){
	int a,b,c,d,e;
	int p,q;
	while(scanf("%d %d %d %d %d",&a,&b,&c,&d,&e)!=EOF){
		p=0;
		q=0;
		if(d<e){
			printf("%d\n",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);
		}else{
			p=(a-2*d)*(b-2*d)*(c-2*d);
			q=8*e*e*e+4*e*e*(a+b+c-6*e);
			if(p>=q){
				printf("%d\n",p);
			}
			else{
				printf("%d\n",q);			}
		}
	}
	return 0;
}