In a class there are seven students (including boys and girls) A, B, C, D, E, F and G. They sit on three benches I, II and III such that there are at least two students on each bench and at least one girl on each bench. C who is a girl student, does not sit with A. E and D. F the boy student sits with only B. A sits on the bench I with his best friends. G sits on the bench III. E is the brother of C?
How many girls are there. Out of these 7 students?