import java.util.Scanner;

public class Solution {

	public static void main(String args[]) {

		Scanner in = new Scanner(System.in);

		int n = in.nextInt();

		int x[] = new int[n];
		int y[] = new int[n];

		for (int i = 0; i < n; i++) {

			x[i] = in.nextInt();
			y[i] = in.nextInt();

		}

		boolean flag = false;

		for (int i = 0; i < n - 1; i++) {

			if (x[i] == x[i + 1])
				flag = true;
			else {
				flag = false;
				break;
			}
		}

		boolean flag2 = false;

		for (int i = 0; i < n - 1; i++) {

			if (y[i] == y[i + 1])
				flag2 = true;
			else {
				flag2 = false;
				break;
			}
		}
		
		if(flag || flag2)
			System.out.println("YES");
		else
			System.out.println("NO");

		in.close();
	}
}