This contest is the first in a series of mock CCO contests.

You will have 4 hours to do 3 problems with full feedback. You may submit no more than 50 submissions per problem. Additionally, the scoreboard will be disabled during the contests.

Although we are giving full feedback, keep in mind the following:

• Unless stated otherwise, your output must match the judge output exactly. The judge will check for proper formatting. Lines should be properly terminated with a newline character.
• Even if no explicit subtasks are mentioned in the problem, suboptimal solutions will still be able to earn marks. All competitors are encouraged to go for partial marks on problems they cannot fully solve.

This contest will not be rated.