Courage
A difficult unit consisting of problems with deceptively short statements. A lot of the difficulty of these problems is setting up an entire framework to attack a simply stated problem. These setups are often more elaborate or detailed than in other problems.
This unit features problems with seemingly short statements but in reality, has a large setup and can be very tricky. The difficulty is that the statement doesn't give a lot to work with so you must sort of make the structures and frameworks, sort of like Free. Often, these problems are at the #3/6 spots, which can make them very scary. Also, this unit may feature longer solutions, but that is normal. There may be longer details you need to address.
Strategies
Some strategies to consider are:
- Not to get scared, have Courage! Sometimes these problems are hard, but sometimes they aren't and it's hard to tell from the problem statement.
- Try more elaborate setups. Look for a base you can use and build from there.
Difficulty
This unit is on the harder side of D units, and every problem in the problem set is worth 9 clubs, as these problems should take a longer time and have more work involved.
Notable problems
These problems have complicated structures that represent some of the most iconic ideas of the Free unit.
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JMO 2016/2: A simpler problem representing this idea.
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IMO 2008/3: A classic NT problem which is also a required problem that's quite instructive.
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USAMO 2007/3: A classic combo problem that's rather nice