n = int(input())


def p_print(*arg):
    print(*arg, flush=True)


def ask(a):
    if len(a) <= 1:
        return 0
    p_print("?", len(a))
    p_print(*sorted(a))
    return int(input())


s = set(range(1, n + 1))
for i in range(1, n + 1):
    s.remove(i)
    if not ask(s):
        s.add(i)


p_print("!", len(s))
p_print(*sorted(s))