def main():
    import sys
    input = sys.stdin.readline

    def ask(A):
        print('?', len(A))
        print(*A)
        sys.stdout.flush()

    N = int(input())
    need = [1] * N
    for i in range(N):
        q = []
        need[i] = 0
        for j in range(N):
            if need[j]:
                q.append(j+1)
        if len(q) == 1:
            need[i] = 1
            need[q[0]-1] = 1
            continue
        ask(q)
        e = int(input())
        if not e:
            need[i] = 1
    ans = []
    for i in range(N):
        if need[i]:
            ans.append(i+1)
    print('!', len(ans))
    print(*ans)
    sys.stdout.flush()
    exit()


if __name__ == '__main__':
    main()