You have 100 books to read and don’t know where to start. You decide that picking 10 will give you a good point to start from. To figure out which ones to start with you lay them out next to each other, numbering them 1-100, and all of them initially closed. This makes a very long line of books.
You are going to walk the line 100 times. The first time you pass, you stop at every book. The second time you pass, you stop at every other book. The third time, you stop at every third book, etc. If the book is open, you close it; if it is closed, you open it. After all of the passes are complete, the books which are open are the ones you decide to read. Which books are open at the end of the 100 passes?
Sorting from lowest to highest, label the open books A through J.
The cache can be located by the following simple equations.
S 33 58.(((F + G) x C) - D + 2A)
E 25 36.(J - 4E + I - H - B +1)
