
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 sum of the first $n$ terms of the sequence $\{a_n\}$ is $S_n$, and $S_n = 2a_n - 2$. The sum of the first $n$ terms of the arithmetic sequence $\{b_n\}$ is $T_n$, and $b_7 = 3, T_5 = -25$. If the sequence $\{c_n\}$ satisfies $c_n = \begin{cases} a_n, & \text{n is odd} \\ b_n, & \text{n is even} \end{cases}$, calculate the sum of the first 8 terms of the sequence $\{c_n\}$.

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