
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
20 natural numbers are written on the board. When one of the numbers was erased, it turned out that one of the remaining numbers became the arithmetic mean of all the others. Find all the numbers that could have been erased.

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