Lateral Entry

Problem: In a college, during the 2nd year of a particular batch, lateral entry students joined the college. Before this, the number of students in all the sections of a branch was equal. After this number of students in most of the classrooms are different. There are $N$ branches in the college. for every $N(i)th$ branch there are $M$ sections. for every $M(I)th$ section students count is given