
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

In each of the 16 compartments of a 4 by 4 box, there is a gold coin. The collector remembers that two adjacent coins (neighbors by side) weigh 9 grams each, while the rest weigh 10 grams each. What is the minimum number of weighings on scales, which show the total weight in grams, needed to identify these two coins?

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