import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {
        public Solution(){}
    
        public static boolean isAllEqual(double[] a){
        for(int i=1; i<a.length; i++){
            if(a[0] != a[i]){
                return false;
            }
        }

        return true;
    }
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        Solution obj = new Solution();
        double x_arr[]=new double[n];
        double y_arr[]=new double[n];
        
        for(int i = 0; i < n; i++){
            int x = in.nextInt();
            int y = in.nextInt();
            x_arr[i] = x;
            y_arr[i] = y;
        }
        if(obj.isAllEqual(x_arr)==true || obj.isAllEqual(y_arr)==true){
            System.out.println("YES");
        }
        else{
            System.out.println("NO");
        }
            
        
    }
}