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

public class Solution {




	public static boolean check(int []x){

		int num = x[0];
		for(int i=1;i<x.length;i++){
			if(num != x[i]){
				return false;
			}
		}
		return true;	
	}

	public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
		int n = in.nextInt();

		int [] allX = new int[n];
		int [] allY = new int[n];

		for(int a0 = 0; a0 < n; a0++){
			allX[a0] = in.nextInt();
			allY[a0] = in.nextInt();
		}
		
		if(check(allX) || check(allY)){
			System.out.println("YES");
		}
        else
		System.out.println("NO");
	}

}