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