ISL 2022 N7
Let be a positive integer and let be a finite set of odd prime numbers. Prove that there is at most one way (modulo rotation and reflection) to place the elements of around a circle such that the product of any two neighbors is of the form for some positive integer . (U.S.A.)
Official text Transcription from NuminaMath olympiads, checked word for word against the official paper. Quoted with source.
Official text: IMO 2022 Shortlist booklet, page 9.
Solutions
Official solution Solution 1 by the IMO Problem Selection Committee
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