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];
        
        boolean vertical = false;
        boolean horizontal = false;
        
        for(int a0 = 0; a0 < n; a0++){
            int x = in.nextInt();
            int y = in.nextInt();
            arrX[a0] = x;
            arrY[a0] = y;
        }
        
        for(int i = 1; i < arrX.length; i++){
            if(arrX[i-1] == arrX[i])
                vertical = true;
            else{
                vertical = false;
                break;
            }
        }
        
        for(int i = 1; i < arrX.length; i++){
            if(arrY[i-1] == arrY[i])
                horizontal = true;
            else{
                horizontal = false;
                break;
            }
        }
        
        if(vertical || horizontal)
            System.out.println("YES");
        else
            System.out.println("NO");
    }
}