
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
The complex numbers \( z_{1}, z_{2} \) satisfy \( \left|z_{1}\right|=\left|z_{2}\right|=1 \), and \( z_{2}-z_{1}=-1 \). Then \( \arg \frac{z_{1}}{z_{2}} = \) _______.

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