N = gets.to_i

def send_query(x, y)
  STDOUT.puts("? #{x} #{y}")
  gets.to_i
end

losers = Hash.new { |h, k| h[k] = [] }
winners = [*1..N]

while winners.size >= 2
  x, y = winners.shift(2)

  winner = send_query(x, y)

  winners << winner

  if x == winner
    losers[x] << y
  else
    losers[y] << x
  end
end

top = winners.first
winners = losers[top]

while winners.size >= 2
  x, y = winners.shift(2)

  winner = send_query(x, y)
  winners << winner
end

STDOUT.puts("! #{winners.first}")