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 points [][] = new int [n][n];
        for(int a0 = 0; a0 < n; a0++){
            int x = in.nextInt();
            int y = in.nextInt();
            points[a0][0] = x;
            points[a0][1] = y;
        }
        int p1 = points[0][0];
        int p2 = points[0][1];
        boolean flag1 = true;
        for(int i=1; i<n; i++){
            if(p1 != points[i][0]){
                flag1 = false;
                break;
            }
        }
        boolean flag2 = true;
        for(int i=1; i<n; i++){
            if(p2 != points[i][1]){
                flag2 = false;
                break;
            }
        }
        if(flag1 == true || flag2 == true){
            System.out.println("YES");
        }
        else{
            System.out.println("NO");
        }
        
    }
}