
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
Alec wishes to construct a string of 6 letters using the letters A, C, G, and N, such that:
- The first three letters are pairwise distinct, and so are the last three letters;
- The first, second, fourth, and fifth letters are pairwise distinct.
In how many ways can he construct the string?

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