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 xOrig=0;
        int yOrig=0;
        int horizontalCt = 0;
        int verticalCt = 0;
        for(int a0 = 0; a0 < n; a0++){
            int x = in.nextInt();
            int y = in.nextInt();
            if(a0 == 0){
                xOrig = x;
                yOrig = y;
            }
            if(x == xOrig){
                verticalCt++;
            }
            if(y == yOrig){
                horizontalCt++;
            }   
        }
        if(horizontalCt == n || verticalCt == n){
            System.out.println("YES");   
        }
        else{
            System.out.println("NO");
        }
    }
}