Logic - To Tell the Truth

Problem: At a certain college campus, liberal arts students always lie, and engineering students always tell the truth. A visitor met a group of three students and asked the first if he was a liberal arts student. While the student responded to the question, the visitor could not hear him. The second student then said that the first had denied being a liberal arts student. Then the third student told the visitor that the first student was, in fact, a liberal arts student. How many of the three students were actually liberal arts students? Which ones, if any, were the liberal arts students?