0 [2, 1, 1, 2, 1]
0 [1, 1, 2, 1]
2 [1, 2]
1 [1]
3 [2, 1, 2]
0 [1, 2]
1 [1]
2 [2, 1]
0 [1]
1 [4, 1, 2, 1]
0 [1, 2, 1]
1 [2]
! 0 [0]
! 0 [0, 0]
! 1 [0, 0, 0]
4
2 1 1 1