#include<iostream>
#include<algorithm>
using namespace std;
long d;
long f(long x1,long y1,long x2,long y2)
{
	if(x2<x1||y2<y1)return 0;
	if(d<abs(x1)+abs(y1))return 0;
	else if(d<min(abs(x1)+abs(y2),abs(x2)+abs(y1)))
	{
		long t=d-abs(x1)-abs(y1)+1;
		return t*(t+1)/2;
	}
	else if(d<max(abs(x1)+abs(y2),abs(x2)+abs(y1)))
	{
		long L=abs(x1)+abs(y2),R=abs(x2)+abs(y1);
		if(L<R)
		{
			long t=L-abs(x1)-abs(y1);
			long u=d-L+1;
			return t*(t+1)/2+u*(y2-y1+1);
		}
		else
		{
			long t=R-abs(x1)-abs(y1);
			long u=d-R+1;
			return t*(t+1)/2+u*(x2-x1+1);
		}
	}
	else if(d<abs(x2)+abs(y2))
	{
		long t=abs(x2)+abs(y2)-d;
		return (x2-x1+1)*(y2-y1+1)-t*(t+1)/2;
	}
	else
	{
		return (x2-x1+1)*(y2-y1+1);
	}
}
main()
{
	long x1,y1,x2,y2;
	cin>>x1>>y1>>x2>>y2>>d;
	long ans=0;
	for(int r=0;r<4;r++)
	{
		ans+=f(max(x1,1L),max(y1,0L),x2,y2);
		long tmp=x1;
		x1=y1;
		y1=-x2;
		x2=y2;
		y2=-tmp;
	}
	if(x1<=0&&0<=x2&&y1<=0&&0<=y2)ans++;
	cout<<ans<<endl;
}