
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
There is a special class of natural numbers where, starting from the third digit from the left, each digit is the sum of the two preceding digits. For example, in the number 21347, each digit from the third onwards follows this rule. Within this class of natural numbers, what is the largest odd number? $\qquad$ .

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