The Social Society of Great Math Teachers conducted a survey on UB campus with 100 students to find out which math teachers are highly recommended for classes. 60 students recommended Dr. JoFe. 70 recommended Dr. Hepburn. 55 recommended Dr. Kounta. It was also shown that 25 recommended all 3 professors, 45 recommended JoFe and Hepburn, 35 recommended JoFe and Kounta and 40 recommended Hepburn and Kounta. How many students from the survey did not recommend Dr. JoFe nor Dr. Hepburn?