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) throws IOException {
      Scanner in = new Scanner(System.in);

      int n = in.nextInt();

      boolean isHorizontal = true;
      boolean isVertical = true;
      int x0 = in.nextInt();
      int y0 = in.nextInt();
      for (int ii=1; (isHorizontal || isVertical) && (ii<n); ++ii) {
         int x1 = in.nextInt();
         int y1 = in.nextInt();
         isHorizontal = isHorizontal && (x1 == x0);
         isVertical = isVertical && (y1 == y0);
      }

      System.out.println((isHorizontal || isVertical) ? "YES" : "NO");
   }
}