/* -*- coding: utf-8 -*-
 *
 * 1830.cc:  No.1830 Balanced Majority - yukicoder
 */

#include<cstdio>
#include<algorithm>
 
using namespace std;

/* constant */

const int MAX_N = 200000;

/* typedef */

/* global variables */

/* subroutines */

int query(int k) {
  printf("? %d\n", k); fflush(stdout);

  int x;
  scanf("%d", &x);
  return x - (k - x);
}

void answer(int l, int r) {
  printf("! %d %d\n", l + 1, r); fflush(stdout);
}

/* main */

int main() {
  int n;
  scanf("%d", &n);

  int s0 = query(1), s1 = query(n - 1);
  if (s0 == s1) { answer(1, n - 1); return 0; }

  s0 = (s0 > 0) ? 1 : -1;
  s1 = (s1 > 0) ? 1 : -1;

  int k0 = 1, k1 = n - 1;
  while (k0 + 1 < k1) {
    int k = (k0 + k1) / 2;

    int sk = query(k);
    if (sk == 0) { k0 = k; break; }
    sk = (sk > 0) ? 1 : -1;

    if (sk * s0 > 0) k0 = k;
    else k1 = k;
  }

  if (k0 < n / 2) answer(k0, n);
  else answer(0, k0);
  return 0;
}