How many movies have Cheung Yuk-King and Lowell Lo Koon-Ting collaborated on?

They have worked on 3 movies together! Their first movie together was It's a Mad, Mad, Mad World II (1988) while their highest rated movie together was Happy Together (1989). They have not worked together since Fist of Fury 1991 II (1992). They are most known for their comedy films together.