Esercitazione 4
https://docs.google.com/spreadsheets/d/1ifQ6aK8wYL1ln91yBaip0Fu5RoNtM7Q1RKmU7mFuE3U/edit?usp=sharing
Esercitazione 5
https://docs.google.com/spreadsheets/d/1m8_k2W-esrWzZuX-1nU-jze1HGUNgM7Xx42HzfVFSaA/edit?usp=sharing
Esercitazione 6
https://docs.google.com/spreadsheets/d/1w-6QN1vfT9aQ6bUzlzwxVBbt-qOdjiux95Npt0zuKXs/edit?usp=sharing