Let's review 3sat_mystery(a,b,c). Since the solution space is still small enough (only eight possible solutions), it is straightforward to implement the function classically and check which input satisfies the function by brute force. In this section, we will show that we can do this in fewer function evaluations on a quantum computer, but, by first going through the exercise classically, it will help us understand the difference in the approach on a quantum computer.