
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
Balázs received a pocket calculator for his birthday. He immediately started adding whole numbers in sequence, starting from 1. When the display showed 3000, he triumphantly looked at his older brother, who had been watching him from the start. His brother then cooled Balázs's enthusiasm by pointing out that he had missed one number. Which number did he leave out?

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