
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
If a gift costs $18 and was sold for $21, then a customer pays with $100 and receives $79 in change, calculate the amount of money Mr. Wang loses when the $100 is returned to the neighbor.

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