The name of this task gives away that this problem will be special. For solving it you won't receive any points. Still, solving it may be useful. What is it going to be all about?
As the easy input, you will be given a puzzle. If you think that you have solved this puzzle, you may submit an output file with your answer. If your answer is wrong, nothing happens. If your answer is right, you will receive -20 minutes (i.e. your total time will now be 20 minutes less) and a new puzzle. Again, you may solve it, submit your answer, etc.
The hard input will be the same, only the puzzles will be harder and the reward for solving each puzzle will be -40 minutes.
Note that you may only make a total of 10 submits for each of the inputs = puzzle sets. Thus the best you can do is to solve 10 easy and 10 hard puzzles without any wrong submits.
You may find the first puzzles in the corresponding input files. Be careful when submitting the output files with the answers, use the correct (upper/lower) case and format your answer in the proper way. Also note that you have to use the correct DIS when submitting the output files – use J1 for submitting answers to the easy puzzles, J2 for submitting answers to the hard puzzles.
Credits:
Problemsetter(s): misof
Contest-related materials: misof
Most successful beta-testers: Tom, Palo, Martin, Kubo, Bee, Yulka, Tono, YoYo