package main

import . "fmt"

func main() {
	var n,a,b,c int64
	Scan(&n,&a,&b,&c)
	ok:=false
	if a < b {
		ok=b<c
	} else {
		ok=c<b
	}
	if ok {
		Println("Yes")
	} else {
		Println("No")
	}
}