input:
3
1
1
2

answer:
4
1 1
1 2
2 3 1
2 3 2

answer:
5
1 1
1 2
2 3 1
2 3 2
3 1 2 3

answer:
3
1 1
1 2
3 1 2 3

answer:
1
3 1 2 3

answer:
1
3 1 2 3

why not

answer:
3
1 1
1 2
3 1 2 3

???

> why not: 1 1

Because 1 1 is effective but not reliable.   It is not reliable because "2 1 2" is also effective.   Therefore there exists a superhero such that adding it to "1 1" makes another effective team, and by the original text of this problem (note that the current problem text is WRONG but the admins don't seem to want to fix it), that makes "1 1" not reliable.

> why not: 1 2
Same reason as "1 1": "1 2" is effective but not reliable because "2 1 2" is also effective.

How is "2 1 2" effective?

Effective according to the problem statement means that all heroes' wishes are satisfied. "2 1 2" doesn't meet this condition because "1" wants to work alone and is instead in a group with "2 2".