
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
All the multiples of nine are written in sequence:

\[9, 18, 27, 36, 45, 54, 63, 72, 81, 90, 99, 108, 117, \ldots\]

and for each of these numbers, the sum of its digits is found:

\[9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 18, 9, 9, \ldots\]

At what position in the sequence will the number 81 first appear, and what will be the number following it? What will appear first in this sequence: the number 27 four times in a row, or the number 36 three times in a row? What else can be said about the alternation of numbers in the sequence?

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