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 tx,ty,cx,cy;cx=cy=0;tx=ty=0;
        for(int a0 = 0; a0 < n; a0++){
            int x = in.nextInt();
            int y = in.nextInt();
            if(a0==0)
            {
                tx=x;ty=y;
            }
            if(tx-x==0)
            {
                cx++;   
            }
            else if(ty-y==0)
            {
                cy++;    
            }
        }
        if(cx==n || cy==n)
        {
            System.out.print("YES");
        }
        else
        {
            System.out.print("NO");
        }
    }
}