
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
On the new island of Tangle, they use an alphabet of 15 letters, A through O. Each word in their language is 5 letters or less, and requires that every word contain the letter A and B at least once. How many words are possible?

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