
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
Among the two-digit numbers formed by the digits 1, 2, 3, 4, 5, with repetition allowed, such as 21, 22, etc., those that contain exactly one even digit "2" are considered to have only one even digit. How many such two-digit numbers are there?

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