
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 typist typed ten letters and addressed ten envelopes, but a scatterbrained secretary distributed these letters into the envelopes without any regard for matching the letter with the recipient. However, each envelope contains exactly one letter. What is the probability that exactly nine letters ended up in their intended envelopes?

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