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[] xs = new int[n];
        int[] ys = new int[n];
        
        for(int a0 = 0; a0 < n; a0++){
            xs[a0] = in.nextInt();
            ys[a0] = in.nextInt();
        }
        
        boolean bx = true;
        for (int i = 1; i < n; i++) {
            if (xs[i] != xs[i-1]) {
                bx = false;
            } 
        }
        boolean by = true;
        for (int i = 1; i < n; i++) {
            if (ys[i] != ys[i-1]) {
                by = false;
            }
        }
        if (bx || by) {
            System.out.println("YES");
        }
        else {
            System.out.println("NO");
        }
    }
}