
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
There are four old Soviet copper coins with denominations of 1 kopeck, 2 kopecks, 3 kopecks, and 5 kopecks. The weight of each coin in grams should numerically equal its denomination. It is known that one of the coins is defective and its weight differs from the normal weight. How can one determine the defective coin using two weighings on a balance scale without additional weights?

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