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();
        int lastX = -100;
        int lastY = -100;
        boolean sameX = true;
        boolean sameY = true;
        for(int a0 = 0; a0 < n; a0++){
            int x = in.nextInt();
            if(lastX != -100 && lastX != x) {
                sameX = false;
            } else {
                lastX = x;
            }
            int y = in.nextInt();
            if(lastY != -100 && lastY != y) {
                sameY = false;
            } else {
                lastY = y;
            }
        }
        
        if(sameX || sameY)
            System.out.println("YES");
        else
            System.out.println("NO");
    }
}