sub g{$_[0]>0&&$_[0]*(1+$_[0])/2}
sub f{
	my($x1,$y1,$x2,$y2,$d)=@_;
	($x1,$x2)=($x2,$x1)if$x1>$x2;
	($y1,$y2)=($y2,$y1)if$y1>$y2;
	return 0 if $x2<0||$y2<0||$d<0;
	$x2-=$x1,$d-=$x1 if$x1>0;
	$y2-=$y1,$d-=$y1 if$y1>0;
	return $d>$x2+$y2?($x2+1)*($y2+1):g($d+1)- g($d-$x2)- g($d-$y2);
}
$/=$";($x1,$y1,$x2,$y2,$d)=<>;
print f($x1,$y1,$x2,$y2,$d)+
f(-$x1-1,$y1,-$x2-1,$y2,$d-1)+
f($x1,-$y1-1,$x2,-$y2-1,$d-1)+
f(-$x1-1,-$y1-1,-$x2-1,-$y2-1,$d-2);