using System;

public class Program

{

    public static void Main()

    {       

        String str = "AAA Z";

        Console.WriteLine(str);

        char[] charArray = str.ToCharArray();  

        for (int i = 0, j = str.Length - 1; i < j; i++, j--)  

        {  

            charArray[i] = str[j]; 

            charArray[j] = str[i];  

        }  

        string strReversed = new string(charArray);  

        Console.WriteLine(strReversed);     

    }

}