
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
A function $f(x)$ defined on $\mathbb{R}$ satisfies $f(x+6)=f(x)$. When $-3 \leq x < -1$, $f(x) = -(x+2)^2$; when $-1 \leq x < 3$, $f(x) = x$. Calculate the value of $f(1) + f(2) + f(3) + \dots + f(2018)$.

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