
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
A thin diverging lens, with an optical power \( D_p = -6 \) diopters, is illuminated by a light beam with a diameter of \( d_1 = 5 \) cm. On a screen parallel to the lens, a bright spot with a diameter of \( d_2 = 20 \) cm is observed. After replacing the thin diverging lens with a thin converging lens, the size of the spot on the screen remains unchanged. Determine the optical power \( D_c \) of the converging lens.

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