논문 11 쪽에 있는 거 구현함. 아래는 실행 결과:

fromList [(0,fromList [0,1,2,3,5]),(1,fromList [0,1,2,3,5]),(2,fromList [0,1,2,3,5]),(3,fromList [3]),(4,fromList [3,4]),(5,fromList [5])]