Question: Which tennis player, Andrei Olhovskiy or Hana Mandlíková, won four Grand Slam singles titles?
Sentence (from "Andrei Olhovskiy"): Andrei Stanislavovich Olhovskiy (Russian: Андрей Станиславович Ольховский ) (born 15 April 1966) is a former tennis player from Russia, who turned professional in 1989.
Relevant evidence: Yes