import java.util.Scanner;

/**
 * Created by merrillm on 6/20/16.
 */
public class PointsOnALine {

    public static void main(String[] args) {
        Scanner scn = new Scanner(System.in);

        int N = scn.nextInt();

        int x = scn.nextInt(), y = scn.nextInt();
        boolean xb = true, yb = true;

        for (int i = 1; i < N && (xb || yb); i++) {
            if (scn.nextInt() != x)
                xb = false;
            if (scn.nextInt() != y)
                yb = false;
        }

        System.out.println((xb || yb) ? "YES" : "NO");
    }

}