#include <bits/stdc++.h>
using namespace std;
#include <atcoder/modint>
using namespace atcoder;
//using mint = modint998244353;
using mint = modint1000000007;
using ll = long long;
using ld = long double;
using pll = pair<ll, ll>;
using tlll = tuple<ll, ll, ll>;
constexpr ll INF = 1LL << 60;
template<class T> bool chmin(T& a, T b) {if (a > b) {a = b; return true;} return false;}
template<class T> bool chmax(T& a, T b) {if (a < b) {a = b; return true;} return false;}
ll safemod(ll A, ll M) {return (A % M + M) % M;}
ll divfloor(ll A, ll B) {if (B < 0) {return divfloor(-A, -B);} return (A - safemod(A, B)) / B;}
ll divceil(ll A, ll B) {if (B < 0) {return divceil(-A, -B);} return divfloor(A + B - 1, B);}
template<class T> void sortunique(vector<T> &V) {sort(V.begin(), V.end()); V.erase(unique(V.begin(), V.end()), V.end());}
#define FINALANS(A) do {cout << (A) << '\n'; exit(0);} while (false)

ll ask(ll K)
{
  cout << "? " << K << endl;
  ll S;
  cin >> S;
  if (S == -1)
    exit(0);
  return 2 * S - K;
}

void ans(ll L, ll R)
{
  cout << "! " << L << " " << R << endl;
  exit(0);
}

int main()
{
  ll N;
  cin >> N;

  ll X = ask(1), Y = ask(N - 1);
  if (X == Y)
    ans(2, N - 1);

  ll ok = 1, ng = N - 1;
  if (X < 0)
    swap(ok, ng);
  
  while (abs(ok - ng) > 1)
  {
    ll mid = (ok + ng) / 2;
    ll Z = ask(mid);
    if (Z >= 0)
      ok = mid;
    else
      ng = mid;
  }

  if (ok >= N / 2)
    ans(1, ok);
  else
    ans(ok + 1, N);
}