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();
        LinkedHashSet<Integer> xList=new LinkedHashSet<Integer>();
        LinkedHashSet<Integer> yList=new LinkedHashSet<Integer>();
        boolean xVal=false;
        boolean yVal=false;
        for(int a0 = 0; a0 < n; a0++){
            int x = in.nextInt();
            int y = in.nextInt();
            xList.add(x);
            yList.add(y);
        }
        if(xList.size()>1 && yList.size()==1){
            System.out.print("YES");
        }
        else if(yList.size()>1 && xList.size()==1){
            System.out.print("YES");
        }
        else
            System.out.print("NO");
    }
}