using System;

using System.Linq;

using System.Collections.Generic;

public class Program

{

    /*

    Input      Output:

bad        bBaAdD

Nice       NniIcCeE

T e S t    Tt eE Ss tT

s E t      sS Ee tT

1!1!1st!   1!1!1sStT!

n00b       nN00bB     

(e.g.)     (eE.gG.)

H3l|@!     Hh3lL|@!

*/

    public static void Main()

    {

        Func<string, string> f=

            s=>string.Concat(s.Select(c=>c+(char.IsLetter(c)?(char)(c^32)+"":"")));

        Console.WriteLine(f("bad"));

        Console.WriteLine(f("Nice"));

        Console.WriteLine(f("T e S t"));

        Console.WriteLine(f("H3l|@!"));

    }

}