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 yesX = true;
        boolean yesY = true;
        
        for(int a0 = 0; a0 < n; a0++)
        {
            int x = in.nextInt();
            int y = in.nextInt();
            
            if(x!=0)
                {
                   yesX=false;
                   if(y!=0)
                      yesY=false;
                }
            
            else if(x==0)
               { 
                if(y!=0)
                  yesY=false;
               }
        }
        
               
        
       if(yesX||yesY==true)
                {
                    if(yesX&&yesY==true)
                        System.out.println("NO");
                
                else if (yesX = true)
                   System.out.println("YES");
                else if (yesX=false)
                   System.out.println("NO");
                else if (yesY = true)
                   System.out.println("YES");
                else if (yesY = false)
                   System.out.println("NO");
                    }
                
            else
                System.out.println("NO");
        
    }
}