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 sc = new Scanner(System.in);
        int n=sc.nextInt();
        int mark = 0;
        int mark2 =0;
        int arr[] = new int[n*2];
        for(int i=0;i<n*2;i++)
        {
            arr[i]= sc.nextInt();
        }
        for(int i=0;i<n;i++)
        {
            int temp = arr[0];
            if(temp == arr[i*2])
                mark = 1;
            else
            {
                mark = 0;
                break;
            }
        }
        for(int i=0;i<n;i++)
        {
            int temp2 = arr[1];
            if(temp2 == arr[i*2+1])
                mark2 = 1;
            else
            {
                mark2 = 0;
                break;
            }
        }
        if(mark==1 || mark2 == 1)
        {
            System.out.println("YES");
        }
        else
            System.out.println("NO");
     
        }
    }