There can be at least another correct solution but it is not clear which one is the answer to the question. For instance,
5 2
1
2
3
4
6

has several solution, some of them are
1   2   1   2
2   1   2   1
1   2   2   1
1   2   1   2
2   1   1   2

Which one should I print?

You may output any correct solution. Problem statement is fixed.