
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 nine-digit number 222222222 is written on a blackboard. The following operation is performed on this number: erase the last digit, multiply the remaining number by 4, then add the erased digit back to the result, and write the number on the blackboard. This process is repeated until a single digit number is obtained. What is this single digit number?

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