
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
Given 21 leaders, with 11 in the front row and 10 in the back row, the Chinese leader in the middle of the front row, and the leaders of the United States and Russia adjacent to the Chinese leader in the front row, calculate the total number of possible arrangements.

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