
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
(1) Use both the Euclidean algorithm and the method of successive subtraction to find the greatest common divisor (GCD) of 204 and 85. (Please show the calculation process.)
(2) Use the Horner's method to calculate the value of the function $f(x) = 2x^4 + 3x^3 + 5x - 4$ when $x = 2$ (Please show the calculation process).

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