long m;x1,x2,y1,y2,d;
#define max(p,q)(p>q?p:q)
#define f(n)(n>0?(n)*(n+1)/2:0)
g(p,q,r,s){
	long x,y,z;
	x=p-max(r,0);
	y=q-max(s,1);
	z=d-max(r,0)-max(s,1);
	m+=x>=0&y>=0?f(z+1)-f(z-y)-f(z-x)+f(z-x-y-1):0;
}
main(){
	scanf("%d%d%d%d%d",&x1,&y1,&x2,&y2,&d);
	m=x1<=0&x2>=0&y1<=0&y2>=0;
	g(x2,y2,x1,y1);
	g(y2,-x1,y1,-x2);
	g(-x1,-y1,-x2,-y2);
	g(-y1,x2,-y2,x1);
	m=!printf("%ld",m);
}