
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 sequence $\left\{a_{n}\right\}$ that satisfies $a_{1}=1$ and $a_{n+1}=\frac{(n+1) a_{n}}{2 n+a_{n}} \left(n \in \mathbb{N}_{+}\right)$, calculate the value of $\sum_{k=1}^{2017} \frac{k}{a_{k}}$.


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