
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
Points $A$ and $B$, located on a circular avenue, are connected by a straight highway segment of 4 km in length, which is the diameter of the circular avenue. From point $A$, a pedestrian went for a walk along the avenue. After 1 hour, he realized he had forgotten his keys and asked a cyclist neighbor to bring them quickly. 

What is the minimum time he can receive the keys if the cyclist's speed on the highway is 15 km/h, on the avenue is 20 km/h, and the pedestrian's speed is 6.5 km/h? The pedestrian may walk towards the cyclist.

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