Kotlin Dev Meetup Exercises Exercise 1: https://pl.kotl.in/tiQHICN_U - classes and data classes Exercise 2: https://pl.kotl.in/6xydYAR5n - sum of even numbers Exercise 3: https://pl.kotl.in/qEuQLVejc - nullability Exercise 4: https://pl.kotl.in/syHv3YbN1 - null-safe drilling