
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 certain residential water usage fee standard is as follows: for a monthly water usage not exceeding $20$ cubic meters, the rate is $a$ yuan per cubic meter; for any excess amount, the rate is $\left(a+2\right)$ yuan per cubic meter. If a certain household in the area used $25$ cubic meters of water last month, the amount of water fee to be paid is ____ yuan.

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