How old were the actors in 17 anni (2013)?

Matteo is a 17-year-old boy who comes to the realization that he is in love with Don Massimo, a young priest of the village that leads the marching band in which Matteo plays the drum. He sees in Massimo a person willing to listen to his fears and desires. For the first time in his life, Matteo feels ready to open up to someone...