
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 in the format $d_1d_2d_3-d_4d_5d_6d_7d_8d_9$. Define this number as memorable if the sequence $d_1d_2d_3$ is identical to either $d_4d_5d_6$ or $d_7d_8d_9$. Each $d_i$ is any of the decimal digits from 0 to 9. Determine the number of different memorable telephone numbers.
A) 1,998,000
B) 1,998,900
C) 1,999,000
D) 2,000,000
E) 2,000,100

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