import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;
import java.util.ArrayList;

public class Solution {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        List<Integer> myXCoords = new ArrayList<Integer>();
        List<Integer> myYCoords = new ArrayList<Integer>();
        for(int a0 = 0; a0 < n; a0++){
            int x = in.nextInt();
            int y = in.nextInt();
            myXCoords.add(x);
            myYCoords.add(y);
        }

        if(areSame(myXCoords) || areSame(myYCoords) ){
            System.out.print("YES");
        }
        else
            System.out.print("NO");
    }

    public static boolean areSame(List<Integer> coords){
        int first = coords.get(0);
        for(int i=0; i< coords.size(); i++){
            if(first!=coords.get(i))
                return false;
        }
        return true;
    }
}