
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 person travels from point A to point B. If he first rides a motorcycle for 12 hours, then switches to a bicycle and rides for 9 hours, he arrives exactly at point B. If he first rides a bicycle for 21 hours, then switches to a motorcycle and rides for 8 hours, he also arrives exactly at point B. How many hours would it take to reach point B by riding a motorcycle for the whole journey?

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