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 Xsame=true;
        boolean Ysame=true;
        int x=0;
        int y=0;
        int slope=Integer.MIN_VALUE;
        for(int a0 = 0; a0 < n; a0++){
            if(a0==0){
                x = in.nextInt();
                y = in.nextInt();
            }else{
             int tempX = in.nextInt();
                if(Xsame && tempX!=x)
                    Xsame=false;
             int tempY = in.nextInt();   
                if(Ysame && tempY!=y)
                    Ysame=false;
            }
             
            
        }
        
            System.out.println((Xsame || Ysame) ?"YES":"NO");
        
    }
}