Added tehtävä 3
Exercise 4 added
Added first Object-oriented region class
Testers now in different classes
Added a few exercises from this week
Added exercise 4
Revert "Added exercise 4"

This reverts commit 38b1f600eebb83d287c5e826eb7e56800cfdfb4d.
Exercise 3 added
Exercises and OOP-implementation for my sudokusolver