εὐζήλως

From LSJ

οὐδείς ἑκὼν πονηρὸς οὐδ' ἄταν ἔχων → no one is willingly wretched or unlucky

Source

Russian (Dvoretsky)

εὐζήλως: старательно, изо всех сил (μελετᾶν Anth.).