There are n students in a class. We want to choose a subset of k students to join a committee. There has to be m 1 number of freshmen, m 2 number of sophomores, m 3 number of juniors, and m 4 number of seniors on the committee. Each student is from one of k departments, where k = m 1 + m 2 + m 3 + m 4 . Exactly one student from each department has to be chosen for the committee. We are given a list of students, their home departments, and their class (freshman, sophomore, junior, or senior). Describe an efficient algorithm based on network flow techniques to select who should be on the committee such that these constraints are all satisfied.