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> setx = new HashSet<>();
        Set<Integer> sety = new HashSet<>();
        for(int a0 = 0; a0 < n; a0++){
            int x = in.nextInt();
            int y = in.nextInt();
            setx.add(x);
            sety.add(y);
        }

        if (setx.size() > 1 && sety.size() > 1)
            System.out.println("NO");
        else
            System.out.println("YES");

    }
}