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();
        boolean x1=true,y1=true;
        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();
            
        }
        for(int i=1;i<n;i++){
           
            if(y[i]!=y[i-1]){
                y1=false;
                break;
            }
        }
        for(int i=1;i<n;i++){
            
            if(x[i]!=x[i-1]){
                x1=false;
                break;
            }
        }
        if(x1||y1)
            System.out.println("YES");
        else
            System.out.println("NO");
    }
}