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();
        boolean sameX = true;
        boolean sameY = true;
        int mx = -1, my = -1;
        for(int a0 = 0; a0 < n && (sameX || sameY); a0++){
            int x = in.nextInt();
            int y = in.nextInt();
            if (a0 == 0) {
                mx = x;
                my = y;
            } else {
                if (sameX && (mx != x)) {
                    sameX = false;
                }
                if (sameY && (my != y)) {
                    sameY = false;
                }
            }
        }
        
        if (sameX || sameY) {
            System.out.println("YES");
        } else {
            System.out.println("NO");
        }
    }
}