@n = gets.to_i
def query(items)
  puts "? #{items.size}"
  puts items.map(&:succ)*' '
  STDOUT.flush
  gets.to_i == 1
end

flg = [false]*@n
q = []
monster = []
@n.times do |i|
  q.push i
  bomb = query(q)
  if bomb
    flg[i] = true
    q.pop
    monster << i
  end
end

puts "! #{monster.size}"
puts monster.map(&:succ)*' '