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