
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
Define a mountain number among 4-digit numbers as one in which the second digit is greater than all other digits, and neither the first nor the fourth digit is zero. How many such mountain numbers exist?

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