in reply to binary conversion
Oh, wait, you wanted more than an answer to that last sentence? Well, if I just give you the answer, you won't know it; you'll just have been told it.
Instead, answer these questions yourself and see if they help you figure out where to attack the problem.
If you get the right answer to those two, you should be well on your way to coming up with the solution. Or it not, at least know just where you lose the story and need a nudge back on track.