
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
A line of soldiers is called irregular if no three consecutive soldiers are in order by height (neither in increasing nor in decreasing order). How many irregular lines can be formed from $n$ soldiers of different heights, for:

a) $n=4$

b) $n=5$?

Present the answer in LaTex format: \boxed{Your answer}
user