#include<stdio.h>
int main()
{int a,b,c,d,e,m,m1,m2,m3;
   while(scanf("%d %d %d %d %d",&a,&b,&c,&d,&e)!=EOF)
   {
	  
	   if(d>=e)
	   {
		   m=(a*c-(a-2*e)*(c-2*e))*e*2+4*(b-2*e)*e*e;
		   m1=(a-2*d)*(b-2*d)*(c-2*d);
		   if(m1>m) m=m1;
	   }
	   else if(e>d)
	   {  m1=(a-2*e)*(c-2*e)*d*2;
		  m2=(a-2*e)*(b-2*e)*d*2;
		  m3=(b-2*e)*(c-2*e)*d*2;
	      m=a*b*c-m1-m2-m3;
	   }
	   
       printf("%d\n",m);
   }
	
	return 0;
}