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 sc = new Scanner(System.in);

		int num = sc.nextInt();

		Set<Integer> x = new HashSet<>();
		Set<Integer> y = new HashSet<>();

		for (int i = 0; i < num; i++)
		{

			x.add(sc.nextInt());
			y.add(sc.nextInt());

		}
		sc.close();

		if (x.size() == 1 || y.size() == 1)
		{
			System.out.println("YES");
		}
		else
		{
			System.out.println("NO");
		}

	}
}