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) {
        try (final Scanner in = new Scanner(System.in)) {
            final Set<Integer> xs = new HashSet<>(), ys = new HashSet<>();
            final int n = in.nextInt();
            for (int i = 0; i < n; i++) {
                xs.add(in.nextInt());
                ys.add(in.nextInt());
            }
            
            System.out.println(((xs.size() == 1) || (ys.size() == 1)) ? "YES" : "NO");
        }
    }
}