
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
In the table, 8 is located in the 3rd row and 2nd column, 2017 is located in the $a$th row and $b$th column. Find $a - b = \quad$
\begin{tabular}{|c|c|c|}
\hline 1 & 4 & 5 \\
\hline 2 & 3 & 6 \\
\hline 9 & 8 & 7 \\
\hline 10 & 13 & 14 \\
\hline 11 & 12 & 15 \\
\hline 18 & 17 & 16 \\
\hline 19 & 22 & 23 \\
\hline 20 & 21 & $\cdots$ \\
\hline
\end{tabular}

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