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