It appears that some of computer science students has learned to analyze the question based on one case study and they can implement it into some kind of algorithm or flowchart. When the student has submitted the work, just as I thought, the steps for rearranging the books were different one another. However, they were still having difficulties in applying their algorithm into a computer program. As we are about to leaving Pascal language, we have discovered that using a Free Pascal Edition (download from freepascal.org) was not recommended, since the last time we have experience the technical difficulties and unstable version of Pascal compiler, which require us to re-install the program.