
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
Evaluate the sum of the sequence: $1940 - 1920 + 1900 - 1880 + \cdots + 20 - 0$.
A) $940$
B) $960$
C) $980$
D) $1000$
E) $1020$

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