from os import cpu_count
import sys,random,bisect
from collections import deque,defaultdict
from heapq import heapify,heappop,heappush
from itertools import permutations
from math import log,gcd

input = lambda :sys.stdin.readline().rstrip()
mi = lambda :map(int,input().split())
li = lambda :list(mi())

def query(k):
    print("? {}".format(k))
    sys.stdout.flush()
    res = int(input())
    assert res!=-1
    return res

def answer(l,r):
    print("! {} {}".format(l,r))
    sys.stdout.flush()

N = int(input())

if query(1)==1:
    first = 1
else:
    first = 0

if query(N-1)==N//2-1:
    end = 1
else:
    end = 0

if first!=end:
    exit(answer(2,N-1))

f_L = 2*first - 1
f_R = 2*(N//2 - end) - (N-1)

L = 1
R = N
while R-L > 1:
    mid = (L+R)//2
    check = 2 * query(mid) - mid

    if f_L * check >= 0:
        L = mid
    else:
        R = mid

if N//2 <= L:
    answer(1,L)
else:
    answer(L+1,N)