---------- Input
[
  [934, [993, 105], [167, [213]]],
  [71, [120, [973]], 135],
  [404, [828, [571]], 945],
]

---------- my solution
934,	993,	105,	167,	213,	71,	120,	973,	135,	404,	828,	571,	945,	

---------- BUKs goal
934,	993,	105,	167,	213,	71,	120,	973,	135,	404,	828,	571,	945,