func main()
	do cui@input()
	var ss: [][]char
	do ss :: cui@input().split(" ")
	var sx: int :: ss[0].toInt(&)
	var sy: int :: ss[1].toInt(&)
	do ss :: cui@input().split(" ")
	var gx: int :: ss[0].toInt(&)
	var gy: int :: ss[1].toInt(&)
	var ans: int :: (gx - sx).abs() + (gy - sy).abs()
	do cui@print("\{ans}\n")
end func