5
2 0 0 1
4 0 0 1
5 0 0 1
6 0 0 1
3 0 0 1

My accepted code outputs this answer:

0, 1, 4
2, 3

Obviously the right answer is 0, 1, 2, 3, 4

My corrected code got WA on test #34 (sbm.id 1787693)