#include <stdio.h>
int main()
{
    int a,b,c,d,e,v1,v2,vm = 0;
    while(scanf("%d %d %d %d %d",&a,&b,&c,&d,&e)!=EOF)
    {
        if(e>d)
        {
            v1=(a-2*e)*(c-2*e)*d*2+(a-2*e)*(b-2*e)*d*2+(b-2*e)*(c-2*e)*d*2;
            vm=a*b*c-v1;
        }
        if(d>=e)
        {
            v1=(a-2*d)*(c-2*d)*(b-2*d);
            v2 = (a - 2 * e) * e * e * 4 + (b - 2 * e) * e * e * 4 + (c - 2 * e) * e * e * 4 + e * e * e * 8;
            if(v2>v1)
                vm=v2;
            else
                vm=v1;
        }
        printf("%d\n",vm);
    }
    return 0;
}