
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
Given that the lengths of the shadows on the 12 solar terms form an arithmetic sequence, and the sum of the lengths of the shadows on the Winter Solstice, the Beginning of Spring, and the Spring Equinox is 37.5 feet, and the length of the shadow on the Grain Rain is 4.5 feet, calculate the length of the shadow on the Winter Solstice.

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