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();
        int[] xs=new int[n];
        int[] ys=new int[n];
        for(int a0 = 0; a0 < n; a0++){
            int x = in.nextInt();
            int y = in.nextInt();
            xs[a0]=x;
            ys[a0]=y;
        }
        boolean xbool=false;
        boolean ybool=false;
        for(int i=1;i<n ;i++)
        {
            if(xs[i]!=xs[0])    xbool=true;
            if(ys[i]!=ys[0])    ybool=true;
        }
        if(xbool&&ybool)    System.out.println("NO");
        else     System.out.println("YES");
    }
}