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];
        for(int a0 = 0; a0 < n; a0++){
             x[a0] = in.nextInt();
             y[a0] = in.nextInt();
        }
        int cntx = 0;
        int cnty = 0;
        for(int i=1; i < n; i++){
            if (x[0] == x[i]){
                cntx++;
            }
            if (y[0] == y[i]){
                cnty++;
            }
        }
        
        if (cntx == n-1 || cnty == n-1){
            System.out.println("YES");
        }
        else{
           System.out.println("NO"); 
        }
    }
}