
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
Calculate the sum of the first 1499 terms of the sequence defined by $\displaystyle a_n = \begin{cases} 15, & \text{if } n \text{ is divisible by } 15 \text{ and } 10; \\ 10, & \text{if } n \text{ is divisible by } 10 \text{ and } 9; \\ 9, & \text{if } n \text{ is divisible by } 9 \text{ and } 15; \\ 0, & \text{otherwise}. \end{cases}$

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