
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
We define a number as a mountain peak number if in a 4-digit number, the second digit is larger than the other three digits. For example, 3827 is a mountain peak number. How many 4-digit mountain peak numbers are there?

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