
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
Calculate $ (1901+1902+1903+\cdots + 2000) - (100+101+102+\cdots + 199) $.
A) $180,000$ 
B) $180,100$ 
C) $181,000$ 
D) $181,100$

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