#include<bits/stdc++.h>
using namespace std;
int main() {
  int N;
  cin >> N;
  int L = 1, R = N;
  for (int i = 0; i < 10; i++) {
    int mid = (L + R) / 2;
    cout << "? " << mid << endl;
    int res;
    cin >> res;
    if (res < mid) {
      R = mid;
    } else {
      L = mid;
    }
  }
  cout << L << ' ' << R << endl;
}