3. At a rock festival, vocalists, guitarists, and drummers met, a total of 121 people. Each vocalist gave a slap on the back of each guitarist, each guitarist gave a slap on the back of each drummer, and each drummer gave a slap on the back of each vocalist. What is the maximum number of slaps on the back that the participants of the festival could have received?
Answer: 4880.

## Examples of how to write the answer:

17

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