Following a liberal arts curriculum, the university provides undergraduate instruction in 40 academic departments and interdisciplinary programs including 57 majors in the humanities, social sciences, natural sciences, and engineering, and enables students to design specialized concentrations or engage in dual degree programs. Dartmouth comprises five constituent schools: the original undergraduate college, the Geisel School of Medicine, the Thayer School of Engineering, the Tuck School of Business, and the Guarini School of Graduate and Advanced Studies. The university also has affiliations with the Dartmouth–Hitchcock Medical Center, the Rockefeller Institute for Public Policy, and the Hopkins Center for the Arts. With a student enrollment of about 6,600, Dartmouth is the smallest university in the Ivy League. Undergraduate admissions are highly selective.