
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 were cards with the digits from 1 to 9 (a total of 9 cards) on the table. Katya selected four cards such that the product of the digits on two of them was equal to the product of the digits on the other two. Then Anton took one more card from the table. As a result, the cards left on the table were 1, 4, 5, and 8. Which digit was on the card that Anton took?

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