import java.io.*;
import java.util.*;

public class Main {

  public static boolean isReflected(int[][] points) {
    //find extremetis while making frequency map of points
    HashMap<Long,Long> map = new HashMap<>();
    
    long xmax = Integer.MIN_VALUE;
    long xmin = Integer.MAX_VALUE;
    
    for(int point[] : points){
        long x = point[0];
        long y = point[1];
        
        xmax = Math.max(xmax , x);
        xmin = Math.min(xmin , x);
        
        //make a unique hash and store it against frequency
        long hash = x * 100000000 + y;  //constraint is 10^8
        
        //we use L to convert it into long format 
        map.put(hash , 1L);
    }
    
    //find mirror between extremetis
    long mirror = xmax + xmin;
    
    for(int point[] : points){
        long x = point[0];
        long y = point[1];
        
        //mirror point 
        long ximg = mirror - x;
        
        //creating unique hash for mirror point
        long hash_img =  ximg * 100000000 + y;
        
        //checking if mirror point exists 
        if(map.containsKey(hash_img) == false)
        return false;
        
    }
    
    return true;

  }

  public static void main(String[] args) {
    Scanner scn = new Scanner(System.in);
    int n = scn.nextInt();

    int[][] points = new int[n][2];
    for (int i = 0; i < points.length; i++) {
      for (int j = 0; j < points[0].length; j++) {
        points[i][j] = scn.nextInt();
      }
    }

    System.out.println(isReflected(points));
  }

}