
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
Consider the function $y=v(x)$ defined by the formula $v(x) = -x + 4\cos(\pi x/2)$. Determine the exact value of $v(-2.67) + v(-1.21) + v(1.21) + v(2.67)$.

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