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();
        boolean x = true;
        boolean y = true;
        int x1 = in.nextInt();
        int y1 = in.nextInt();
        for(int a0 = 1; a0 < n; a0++){
            int x2 = in.nextInt();
            int y2 = in.nextInt();
            x = x && x2 == x1;
            y = y && y2 == y1;
        }
        System.out.println(x || y ? "YES" : "NO");
    }
}