
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
In the sum \((1-2-3+4)+(5-6-7+8)+\ldots+(2009-2010-2011+2012)+(2013-2014-2015)\), all numbers ending in 0 were crossed out. Find the value of the resulting expression.

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