
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
Given the function $f(n)=\begin{cases}n^{2}, & \text{if } n \text{ is odd} \\ -n^{2}, & \text{if } n \text{ is even}\end{cases}$ and $a_{n}=f(n)+f(n+1)$, then the sum $a_{1}+a_{2}+a_{3}+\cdots+a_{2018}=$ ?

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