using System;

​

public class Program

{

    static void Main(string[] args)

    {

        Console.WriteLine(test("Pizza"));

        Console.WriteLine(test(""));

        Console.WriteLine(test("xy"));

        Console.ReadLine();

    }

​

    public static string test(string str)

    {

        return str.Length > 1 ? str.Substring(str.Length - 1) + str.Substring(1, str.Length - 2) + str.Substring(0, 1) : str;

    }

}