Michael and Hotel

Michael and Brian are stuck in a hotel with $$$n$$$ rooms, numbered from $$$1$$$ to $$$n$$$, and need to find each other. But this hotel's doors are all locked and the only way of getting around is by using the teleporters in each room. Room $$$i$$$ has a teleporter that will take you to room $$$a_i$$$ (it might be that $$$a_i = i$$$). But they don't know the values of $$$a_1,a_2, \dots, a_n$$$.

Instead, they can call up the front desk to ask queries. In one query, they give a room $$$u$$$, a positive integer $$$k$$$, and a set of rooms $$$S$$$. The hotel concierge answers whether a person starting in room $$$u$$$, and using the teleporters $$$k$$$ times, ends up in a room in $$$S$$$.

Brian is in room $$$1$$$. Michael wants to know the set $$$A$$$ of rooms so that if he starts in one of those rooms they can use the teleporters to meet up. He can ask at most $$$2000$$$ queries.

The values $$$a_1, a_2, \dots, a_n$$$ are fixed before the start of the interaction and do not depend on your queries. In other words, the interactor is not adaptive.

To ask a query, print a line in the format "? u k |S| S_1 S_2 ... S_|S|" with $$$1 \leq u, S_1, \ldots, S_{|S|} \leq n$$$, all the $$$S_i$$$ distinct, and $$$1 \leq k \leq 10^9$$$.

As a response to the query you will get "1" if the answer is yes, and "0" if the answer is no.

To output an answer, you should print "! |A| A_1 A_2 ... A_|A|" with $$$1 \leq A_1, \ldots, A_{|A|} \leq n$$$ all distinct. Printing the answer doesn't count as a query.

See the interaction example for more clarity.

If you ask too many queries or you ask a malformed query, you will get Wrong answer.

After printing a query do not forget to output the end of line and flush the output. Otherwise, you will get Idleness limit exceeded. To do this, use:

• fflush(stdout) or cout.flush() in C++;
• System.out.flush() in Java;
• flush(output) in Pascal;
• stdout.flush() in Python;
• see the documentation for other languages.

Hack format

For the hacks use the following format.

The first line should contain $$$n$$$ — the number of rooms.

The second line should contains $$$n$$$ integers $$$a_1, a_2, \dots, a_n$$$ — the teleporter in room $$$i$$$ leads to room $$$a_i$$$.