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 flag = 0;
        int temp = 0;
        for(int a0 = 0; a0 < n-1; a0++){
            if(x[a0] != x[a0+1]){
                flag = 1;
                break;
            }
        }
        for(int a0 = 0; a0 < n-1; a0++){
            if(y[a0] != y[a0+1]){
                temp = 1;
                break;
            }
        }
        if(flag ==0 || temp == 0){
        System.out.println("YES");
        return;    
        }else{
        System.out.println("NO");
        return;
        }
        
        
    }
}