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();
        Set<Integer> xSet = new TreeSet<Integer>();
        Set<Integer> ySet = new TreeSet<Integer>();
        for(int a0 = 0; a0 < n; a0++){
            int x = in.nextInt();
            int y = in.nextInt();
            xSet.add(x);
            ySet.add(y);
        }
        if(xSet.size()==1 || ySet.size()==1)
        	System.out.println("YES");
        else
        	System.out.println("NO");
        in.close();
    }
}