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[] arrx = new int[n];
        int[] arry = new int[n];
        for(int a0 = 0; a0 < n; a0++){
            int x = in.nextInt();
            int y = in.nextInt();
            arrx[a0] = x;
            arry[a0] = y;
        }
        boolean fx = false;
        int z = arrx[0];
        for(int a0 = 1; a0 < n; a0++){
            if(arrx[a0] != z){
                fx = true;
            }
        }
        if(fx == false){
            System.out.println("YES");
        }else{
            boolean fy = false;
            z = arry[0];
            for(int a0 = 1; a0 < n; a0++){
                if(arry[a0] != z){
                    fy = true;
                }
            }
            if(fy == false){
                System.out.println("YES");
            }else{
                System.out.println("NO");
            }
        }
    }
}