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[] xi = new int[n];
        int[] yi = new int[n];
        
        for(int a0 = 0; a0 < n; a0++){
            xi[a0] = in.nextInt();
            yi[a0] = in.nextInt();
        }
        if(n==0 ||n == 1){
            System.out.println("YES");
            return;   
        }  
        int x = xi[0];
        int y = yi[0];
        if(xi[1]== x ){
            for(int i=1;i<n;i++){
                if(xi[i]!=x){
                    System.out.println("NO");
                    return;
                }
                    
            }
        }
        
        if(yi[1]== y ){
            for(int i=1;i<n;i++){
                if(yi[i]!=y){
                    System.out.println("NO");
                    return;
                }
                    
            }
        }               
        System.out.println("YES");
    }
}