import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int previousx = 0;
        int previousy = 0;
        boolean checkx=false,checky=false;
        String result="";
        for(int a0 = 0; a0 < n; a0++){
            int x = in.nextInt();
            int y = in.nextInt(); 
            if(a0==0){
            	previousx=x;
            	previousy=y;
            }
           if(a0>=1){
                if(previousx==x){
                	if(a0==1){
                		checkx = true;
                	}
                	checkx = checkx;
                }if(previousx!=x){
                    checkx = false;
                }if(previousy==y){
                	if(a0==1){
                		checky = true;
                	}
                    checky = checky;
                }if(previousy!=y){
                    checky = false;
                }
            }
            
        }
        
        if(checkx||checky){
            System.out.println("YES");
        }else{
            System.out.println("NO");
        }
    } 
}