Recently I came across with the topcoder problem 'Cassette'.However,I can only find the editorial but not the problem statement.It shows that "Problem Statement not available".I have also found that some other really old topcoder problems don't have available problem statements either,like this one.

So is there an archived version or someone still remembers the problem statement?I think it may be a well-known one:D.I will be very grateful for your help!