#include<stdio.h>
int main(){
	int a,b,c,d,e;
	int v1,v2,v3;
	while(scanf("%d%d%d%d%d",&a,&b,&c,&d,&e)!=EOF){
	if(d<e){
		v3=(a-2*e)*(c-2*e)*d*2+(b-2*e)*(c-2*e)*d*2+(a-2*e)*(b-2*e)*d*2;
		v1=a*b*c-v3;
		printf("%d\n",v1);
	}
	else if(d>=e){
		v2=(a-2*d)*(b-2*d)*(c-2*d);
		v1=e*e*(a+b+c)*4-e*e*e*16;
		if(v1>v2)
		printf("%d\n",v1);
		else
		printf("%d\n",v2);
	}
}
	return 0;
}