Beloved integers - PRIMOS print job
Happy student memories are awakened by one of my (long time ago) colleague students, who found a rather amusing hole. We were only allowed to print 4 jobs per semester. However, as my esteemed colleague found, the arguments to the print command included a "number of copies" argument. Promptly he tried -1 copies and voila, he had 5 print jobs for the semester and one paper copy at the printer.
Happy memories, indeed.