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 xflag=0,yflag=0, i,j,xcomparator,ycomparator;
        List<Integer> xlist=new ArrayList<Integer>();
        List<Integer> ylist=new ArrayList<Integer>();
        for(int a0 = 0; a0 < n; a0++){
            int x = in.nextInt();
            xlist.add(x);
            int y = in.nextInt();
            ylist.add(y);
        }
            xcomparator=xlist.get(0);    
            ycomparator=ylist.get(0);    
            for (i=1;i<xlist.size();i++)
            {
                if (xcomparator==xlist.get(i))
                    {xflag=1;}
                else
                    {
                    xflag=0;
                    break;
                    }
            }
            if(xflag!=1)
            {
                for (j=1;j<ylist.size();j++)
                {
                 if (ycomparator==ylist.get(j))
                    {yflag=1;}
                    else
                    {
                    yflag=0;
                    break;
                    }
                }
                if(yflag==1)
                {System.out.println("YES");}
            else if (yflag==0)
                {System.out.println("NO");}
            }
            else if (xflag==1)
            {
                System.out.println("YES");    
            }
            
            
        
    }
}