import java.util.Scanner;

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();
    }
    if (isOnOneLine(xs) || isOnOneLine(ys)) {
      System.out.println("YES");
    } else {
      System.out.println("NO");
    }
  }

  static boolean isOnOneLine(int[] ns) {
    for (int i = 0; i < ns.length - 1; i++) {
      if ((ns[i] ^ ns[i + 1]) != 0) {
        return false;
      }
    }
    return true;
  }
}