
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
The annual average concentration of $PM2.5$ in a certain city two years ago was $50$ micrograms per cubic meter. Last year, it decreased by $10\%$ compared to the previous year. If this year the annual average concentration of $PM2.5$ decreases by $10\%$ compared to last year, then this year the annual average concentration of $PM2.5$ will be ____ micrograms per cubic meter.

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