from strutils import parseInt
from sequtils import mapIt

let N = stdin.readLine.parseInt

var participants = (1..N).mapIt(it)

proc ask(x, y: int): int =
  echo "? ", x, " ", y
  stdin.readLine.parseInt

var next = newSeq[int]()
while participants.len > 2:
  next = @[]
  for i in countup(1, participants.len, 2):
    let ans = ask(participants[i - 1], participants[i])
    next.add(ans)
  participants = next

let ans = ask(participants[0], participants[1])
echo "! ", participants[participants.find(ans) xor 1]