
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
We define \( a \star b = a \times a - b \times b \). Find the value of \( 3 \star 2 + 4 \star 3 + 5 \star 4 + \cdots + 20 \star 19 \).

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