using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine( CheckIsRotation("apple","leapp"));

        Console.WriteLine( CheckIsRotation("apple","alepp"));

    }

    public static bool CheckIsRotation( string s1, string s2)

    {

        if(s1 == null || s2 == null)

            return false;

        if(s1.Length == s2.Length && s1.Length > 0)

        {

            string temp = s2 + s2;

            if( temp.IndexOf(s1) > 0)

                return true;

        }

        return false;

    }

}