
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 the explicit formula for sequence $\{a_n\}$ is $a_n=2n-3$, group the sequence as follows. Group 1: $a_1$; Group 2: $a_2, a_3$; ...; if the last number in the k-th group is $a_m$, then the (k+1) numbers in the (k+1)-th group are arranged in order: $a_{m+1}, a_{m+2}, ..., a_{m+k+1}$ (where $m, k \in \mathbb{N}^{*}$). What is the first number of the 10th group?

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