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[] x = new int[n];
        int[] y = new int[n];
        int flag=0;
        if(n>=2)
        {
           
            for(int a0 = 0; a0 < n; a0++){
                   
                 x[a0]  = in.nextInt();
                 y[a0] = in.nextInt();
            }
            
            for(int i=1;i<x.length;i++)
            {
              
                if(x[i]==x[i-1])
                {
                       
                    flag=1;
                    
                }
                else if(y[i]==y[i-1])
                {
                    flag=1;
                }
                else if((i==x.length-1) && flag==0)
                    System.out.println("NO");
                else if(i==x.length-1 && flag==0)
                    System.out.println("NO");
            }
           if(flag==1)
            System.out.println("YES");   
        }
        else 
            System.out.println("YES");
    }
}