solution.py

# Polycarpus works as a DJ in the best Berland nightclub, and he often uses dubstep music in his performance.
# Recently, he has decided to take a couple of old songs and make dubstep remixes from them.

# Let's assume that a song consists of some number of words (that don't contain WUB).
# To make the dubstep remix of this song,
# Polycarpus inserts a certain number of words "WUB" before the first word of the song (the number may be zero),
# after the last word (the number may be zero), and between words (at least one between any pair of neighbouring words),
# and then the boy glues together all the words, including "WUB", in one string and plays the song at the club.

# For example, a song with words "I AM X" can transform into a dubstep remix as "WUBWUBIWUBAMWUBWUBX"
# and cannot transform into "WUBWUBIAMWUBX".

# Recently, Jonny has heard Polycarpus's new dubstep track, but since he isn't into modern music,
# he decided to find out what was the initial song that Polycarpus remixed.
# Help Jonny restore the original song.

# Input
# The input consists of a single non-empty string, consisting only of uppercase English letters,
# the string's length doesn't exceed 200 characters

# Output
# Return the words of the initial song that Polycarpus used to make a dubsteb remix. Separate the words with a space.

# Examples
# song_decoder("WUBWEWUBAREWUBWUBTHEWUBCHAMPIONSWUBMYWUBFRIENDWUB")
# =>  WE ARE THE CHAMPIONS MY FRIEND
import re


def song_decoder(song):
    return re.sub('(WUB)+', ' ', song).strip()