
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 that four 'A's, four 'B's, four 'C's, and four 'D's are placed in the sixteen spaces of a 4x4 grid so that each row and column contains one of each letter, if 'A' is placed in the upper right corner, calculate the number of possible arrangements.

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