
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
On the Arctic Circle ($60^{\circ}$), there are two locations $A$ and $B$. The arc length between them on this latitude circle is equal to $\frac{\pi R}{2}$ ($R$ is the radius of the Earth). What is the spherical distance between locations $A$ and $B$?

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