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();
        ArrayList<Integer> xArr = new ArrayList<>();
        ArrayList<Integer> yArr = new ArrayList<>();
        for(int a0 = 0; a0 < n; a0++){
            xArr.add(in.nextInt());
            yArr.add(in.nextInt());
        }    
        boolean isOnX = true;
        boolean isOnY = true;
        for(int i=0;i<n-1;i++) {
            if(!Objects.equals(xArr.get(i), xArr.get(i+1))) {
                isOnX = false;
            }
            if(!Objects.equals(yArr.get(i), yArr.get(i+1))) {
                isOnY = false;
            }
        }
        
        if(isOnX || isOnY)
            System.out.println("YES");
        else
            System.out.println("NO");
        
    }
}