__author__ = 'Mors'
from random import randint


moves = ["F", "F'", "R", "R'", "L", "L'", "U", "U'", "D", "D'", "B", "B'", "F2", "R2", "L2", "U2", "D2", "B2"]
scramble = []

lenght = len(scramble)
lenght_moves = len(moves) - 1

def good_move(scramble, lenght):
    if scramble[lenght]  ==  "R" or scramble[lenght] == "R'" or scramble[lenght] == "R2":
        if scramble[lenght - 1]  ==  "R" or scramble[lenght - 1] == "R'" or scramble[lenght - 1] == "R2":
            return False
    if scramble[lenght]  ==  "L" or scramble[lenght] == "L'" or scramble[lenght] == "L2":
        if scramble[lenght - 1]  ==  "L" or scramble[lenght - 1] == "L'" or scramble[lenght - 1] == "L2":
            return False
    if scramble[lenght]  ==  "F" or scramble[lenght] == "F'" or scramble[lenght] == "F2":
        if scramble[lenght - 1]  ==  "F" or scramble[lenght - 1] == "F'" or scramble[lenght - 1] == "F2":
            return False
    if scramble[lenght]  ==  "U" or scramble[lenght] == "U'" or scramble[lenght] == "U2":
        if scramble[lenght - 1]  ==  "U" or scramble[lenght - 1] == "U'" or scramble[lenght - 1] == "U2":
            return False
    if scramble[lenght]  ==  "D" or scramble[lenght] == "D'" or scramble[lenght] == "D2":
        if scramble[lenght - 1]  ==  "D" or scramble[lenght - 1] == "D'" or scramble[lenght - 1] == "D2":
            return False
    if scramble[lenght]  ==  "B" or scramble[lenght] == "B'" or scramble[lenght] == "B2":
        if scramble[lenght - 1]  ==  "B" or scramble[lenght - 1] == "B'" or scramble[lenght - 1] == "B2":
            return False

    return True





while (lenght < 20):
    print (lenght)
    print (scramble)
    random = randint(0, lenght_moves)
    if lenght - 1 >= 1:
        if good_move(scramble, lenght - 1) == False:
            print ("I'm here")
            while (good_move(scramble, lenght - 1)) != False:
                random = randint(0, lenght_moves)
                print (random)
                scramble.remove(lenght - 1)
                scramble.append(moves[random])
        else:
            scramble.append(moves[random])

    else:
        scramble.append(moves[random])

    lenght = len(scramble)

print (scramble)