"""
Can we save them? Beta Rabbit is trying to break into a lab that contains the only known zombie cure - but there's an obstacle. The door will only open if a challenge is solved correctly. The future of the zombified rabbit population is at stake, so Beta reads the challenge: There is a scale with an object on the left-hand side, whose mass is given in some number of units. Predictably, the task is to balance the two sides. But there is a catch: You only have this peculiar weight set, having masses 1, 3, 9, 27, ... units. That is, one for each power of 3. Being a brilliant mathematician, Beta Rabbit quickly discovers that any number of units of mass can be balanced exactly using this set.

To help Beta get into the room, write a method called answer(x), which outputs a list of strings representing where the weights should be placed, in order for the two sides to be balanced, assuming that weight on the left has mass x units.

The first element of the output list should correspond to the 1-unit weight, the second element to the 3-unit weight, and so on. Each string is one of:

"L" : put weight on left-hand side
"R" : put weight on right-hand side
"-" : do not use weight
To ensure that the output is the smallest possible, the last element of the list must not be "-".
x will always be a positive integer, no larger than 1000000000.
"""
from math import log

def answer(x):
    order = []
    step = int(log(x * 2, 3)) + 1
    for n in range(step):
        y = round(float(x / (3.0 ** n))) % 3
        if y == 1:
            order.append("R")
        elif y == 2:
            order.append("L")
        else:
            order.append("-")
    return order
