package main

import . "fmt"
import . "os"
import bf "bufio"

func main() {
	rd:=bf.NewReader(Stdin)
	var n int
	Fscan(rd,&n)
	for ;n>0;n-- {
		var v,w int
		Fscan(rd,&v,&w)
		if w == 1 {
			Println("Yes")
			return
		}
	}
	Println("No")
}