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[] xs = new int[n];
        int[] ys = new int[n];
        for(int a0 = 0; a0 < n; a0++){
            xs[a0] = in.nextInt();
            ys[a0] = in.nextInt();
        }
        if (allSame(xs) || allSame(ys)) {
            System.out.println("YES");
        } else {
            System.out.println("NO");
        }
    }
    
    private static boolean allSame(int[] list) {
        if (list.length == 0) {
            return true;
        }
        int first = list[0];
        for (int i = 1; i < list.length; i++) {
            if (first != list[i]) {
                return false;
            }
        }
        return true;
    }
}