
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
Consider a $9$-digit telephone number formatted as $d_1d_2d_3d_8-d_4d_5d_6d_7d_9$. Define the number as memorable if the sequence $d_1d_2d_3d_8$ matches either $d_4d_5d_6d_7$ or $d_5d_6d_7d_9$. Each digit $d_i$ can be any decimal digit from $0$ to $9$. Calculate the number of different memorable telephone numbers.
A) 198990
B) 199990
C) 200000
D) 201000
E) 202000

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