# The Finnish death metal band Demilich released an album in 1993 called
# "Nespithe". The liner notes, as well as the album title and one song title,
# are written in code: start at the end of the phrase, group the letters in
# three, and reverse the groups' order.

def encode(string):
    string = string.replace(" ","")
    newstr = ""
    for i in range(0,len(string),3):
        newstr = string[i:i+3] + newstr
    return newstr.upper()

def decode(string):
    string = string.replace(" ","")
    newstr = ""
    for i in range(len(string),2,-3):
        newstr += string[i-3:i]
    newstr += string[0:i%3]
    return newstr.upper()

fkey = None
while fkey != "q":
    function = input("[E]ncode, [D]ecode, or [Q]uit? ")
    fkey = function[0].lower()
    if fkey == "q":
        continue
    elif fkey == "e":
        string = input("String to encode: ")
        print(encode(string))
    elif fkey == "d":
        string = input("String to decode: ")
        print(decode(string))

print("Flying out of this world to another land...")