How many movies have Kim Hui-su and Seo Byeong-su collaborated on?

They have worked on 4 movies together! Their first movie together was 7 Women P.O.W's (1965) while their highest rated movie together was A Woman After a Killer Butterfly (1978). They have not worked together since A Woman After a Killer Butterfly (1978). They are most known for their romance films together.