I saw on the chancing profile that USAMO qualification is a Tier A 'Non-art competition' activity for the chancing profile. What about the AIME? A few thousand students (not sure of the exact #) qualify for the AIME every year.
Any competition that isn't writing (they have a separate spot for that) or art-related is meant to take the spot of "Non-Art Competition". Even though there aren't concrete numbers, it is a tier A activity.
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