Amherst is an exclusively undergraduate four-year institution; the school enrolled 1,855 students in fall 2018. Admissions is highly selective, and it frequently ranks at or near the top in most rankings of liberal arts schools. Students choose courses from 38 major programs in an open curriculum and are not required to study a core curriculum or fulfill any distribution requirements; students may also design their own interdisciplinary major. Amherst competes in the New England Small College Athletic Conference. Amherst has historically had close relationships and rivalries with Williams College and Wesleyan University, which form the Little Three colleges. The college is also a member of the Five College Consortium, which allows its students to attend classes at four other Pioneer Valley institutions: Mount Holyoke College, Smith College, Hampshire College, and the University of Massachusetts Amherst.