If I hold a call option for over a year and then exercise it, are those shares considered long or short term gains?

I bought a call option in Jan 2021 that expired in Jan 2022. I exercised that option before expiration, converting it to shares. Are those shares “purchased” in Jan 2021 (the date of the option acquisition) considered a LTG, or did I “buy” them Jan 2022 making them currently a STG?