DMOJ will host mirror contests for the Canadian Computing Olympiad.

This problem set will come from day 1 of the competition. This contest will not be rated.

There will be 3 problems to solve in 4 hours. Partial scoring may be available on some problems. The maximum score on a single problem is 25*.

You may submit to each problem at most 50 times.

* The maximum score on problem 2 is 12. The authors of the problem had an incorrect reference solution at the time of the CCO, and it is currently unknown whether any efficient solutions exist to solve the subtasks worth the remaining 13 points. Since we do not know of a way to verify the correctness of a user's submission to this problem without having a correct reference solution, DMOJ will only evaluate subtasks worth the first 12 points. CCO contestants were also only evaluated on the first 12 points for calculating their final score.