Where does “τέσσᾰρᾰ” come from?

τέσσᾰρᾰ (Ancient Greek) comes from Ancient Greek τέσσᾰρες, from Proto-Hellenic kʷétwores, from Proto-Indo-European kʷetwóres, from Proto-Indo-European kʷe- — and.

τέσσᾰρᾰ (Ancient Greek): four