#include<stdio.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;
			V=(a-e-e)*(b-e-e)*2+(b-e-e)*(c-e-e)*2+(a-e-e)*(c-e-e)*2;
			if(d<e)
			{
				printf("%d\n",a*b*c-V*d);
			}
			else
			{
				int V1=0,V2=0;
				V2=a*e*e*4+(b-e-e)*e*e*4+(c-e-e)*e*e*4;
				V1=(a-d-d)*(b-d-d)*(c-d-d);
				if((a-d-d)<0&&(b-d-d)<0&&(c-d-d)<0)
				V1=0;
				if(V1>V2)
				    printf("%d\n",V1);
				else
				{
					printf("%d\n",V2);
				}
			}
	}
	return 0;
}