Of 30 students, exactly 15 are athletes, 10 are on the student council, and 8 are in the band. Only 3 athletes are in the band and only 4 non-athletes are in the band. In the group, a person who is an athlete may be in the band and in the student council but not in one or the other alone. How many of the 30 students are not athletes in the student council or band?
