UTF-8がどうとかいわれたので日本語けしてインデントつけたら動いたみたいです。
19を入力してみました。

$ ./collatz.exe
19
input num
Z/pZ : [0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18]
A : [[0],[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18]]
Z/3pZ : [0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56]
B : [[1,2,4,7,8,14,16,25,28,29,32,41,43,49,50,53,55,56],[5,10,11,13,17,20,22,23,26,31,34,35,37,40,44,46,47,52]]
(3) tuple : [(0,Just 0),(1,Just 0),(1,Just 1),(1,Nothing)]
(4) A' No. : [0]
C : [[5,10,11,20,22,40,44,80,83,88,91,127,131,149,151,160,161,166],[13,23,26,37,46,52,67,74,79,92,97,104,119,125,134,145,148,158],[17,31,34,35,47,62,68,70,77,94,101,103,109,124,136,137,140,154]]
(6) tuple : [(0,Nothing),(0,Just 1),(0,Just 0),(0,Just 2)]
(7) B' No. : []