#include<stdio.h>
int main()
{
	int a,b,c,d,e,i;
	int V;
	while(scanf("%d %d %d %d %d",&a,&b,&c,&d,&e)!=EOF){
		V=0;
		int V2=0;
		if(d>=e){
			//V=a*b*c-(a-2*e)*(c-2*e)*b-(a-2*e)*(b-2*e)*2*e-(c-2*e)*(b-2*e)*2*e;
			V=a*e*e*4+(b-2*e)*e*e*4+(c-2*e)*e*e*4;
			V2=(a-2*d)*(b-2*d)*(c-2*d);
			if(V<V2){
				V=V2;
			}
		} else if(d<e){
			V=a*b*c-2*d*((a-2*e)*(b-2*e)+(a-2*e)*(c-2*e)+(c-2*e)*(b-2*e));
		}
		
		
		printf("%d\n",V);
	}
	return 0;
}