
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
Call a positive integer modified-monotonous if:
- It is a one-digit number; or
- Its digits, read from left to right, form a non-decreasing or non-increasing sequence where the digit '0' can be repeated once if it appears. For example, $4$, $12338$, and $86640$ are modified-monotonous, but $88$ and $20449$ are not. How many modified-monotonous positive integers can be formed using the digits $0$ to $8$?
**A)** 2360
**B)** 2426
**C)** 2548
**D)** 2590
**E)** 2702

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