def decrypt(s:String, dec:Int):String = {

    return s.foldLeft("") {
      case (acc, char) if char.isLetter =>
        val c =  (char.toLower + dec).toChar;
        if(c > 'z')
            acc + (c - 'z' + 'a' - 1).toChar // Greater than z, force back to the start of the alphabet
        else
            acc + c.toChar  // Append the char
      case (acc, char) => acc + char // Not a letter, ignore and append to
    }

  }