package main

import . "fmt"

func main() {
	var r,c,sy,sx,gy,gx int
	Scan(&r,&c,&sy,&sx,&gy,&gx)
	Println(abs(gy-sy)+abs(gx-sx))
}

func abs(a int) int {
	if a  < 0 {
		return -a
	}
	return a
}