
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
Evaluate the expression:

\[
\frac{1-\frac{1}{3}}{1 \times \frac{1}{2} \times \frac{1}{3}}+\frac{\frac{1}{3}-\frac{1}{5}}{\frac{1}{3} \times \frac{1}{4} \times \frac{1}{5}}+\cdots+\frac{\frac{1}{2015}-\frac{1}{2017}}{\frac{1}{2015} \times \frac{1}{2016} \times \frac{1}{2017}}
\]

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