#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using V = vector<ll>;
using VV = vector<V>;
using VVV = vector<VV>;
using VVVV = vector<VVV>;
using VVVVV = vector<VVVV>;
using VVVVVV = vector<VVVVV>;
using VS = vector<string>;
using VB = vector<bool>;
using VVB = vector<VB>;
using P = pair<ll,ll>;
using M = map<ll,ll>;
using Q = queue<ll>;
using PQ = priority_queue<ll>;
using PQG = priority_queue<ll,V,greater<ll>>;
using S = set<ll>;
using VP = vector<P>;
const ll MOD = 1000000007;
const ll mod = 998244353;
const ll INF = 1LL << 60;
#define rep(i,n) for(ll i = 0; i < n; i++)
#define rep2(i,s,n) for(ll i = s; i < n; i++)
#define per(i,n) for(ll i = n-1; i >= 0; i--)
#define per2(i,s,n) for(ll i = n-1; i >= s; i--)
#define all(x) (x).begin(),(x).end()
#define rall(x) (x).rbegin(),(x).rend()
#define fi first
#define se second
#define pb push_back
#define pf push_front
#define ppb pop_back
#define ppf pop_front
#define eb emplace_back
#define lb lower_bound
#define ub upper_bound
template<class T>bool chmin(T&a, const T&b){if(a>b){a=b;return true;}return false;}
template<class T>bool chmax(T&a, const T&b){if(a<b){a=b;return true;}return false;}
template<class T>void Vin(vector<T>&a){rep(i,(int)a.size())cin>>a[i];}
template<class T>void VVin(vector<vector<T>>&a){rep(i,(ll)a.size())Vin(a[i]);}
template<class T>void Vout(const vector<T>&a){rep(i,(ll)a.size()-1)cout<<a[i]<<" ";cout<<a.back()<<endl;}
template<class T>void Voutl(const vector<T>&a){rep(i,(ll)a.size())cout<<a[i]<<endl;}
ll power(ll a,ll b,const ll&M){a%=M;ll res=1;while(b>0){if(b&1)res=res*a%M;a=a*a%M;b>>=1;}return res;}
const ll H[4] = {0,1,0,-1}, W[4] = {1,0,-1,0};

void f(int a, ll &b) {
  printf("? %d\n", a);
  cin >> b;
  b = b * 2 - a;
}

void g(int a, int b) {
  printf("! %d %d", a, b);
  cout << endl;
}

int main() {
  ll n;
  cin >> n;
  ll a, b;
  f(1, a);
  f(n-1, b);
  if(a == b) {
    g(2, n-1);
    return 0;
  }
  ll l = 1, r = n-1;
  while(r - l > 1) {
    ll mid = (r - l) / 2, c;
    f(mid,c);
    if(c == 0 || c == -1) {
      if(mid < n / 2) g(mid+1, n);
      else g(1, mid);
      return 0;
    }
    if(a * c < 0) r = mid;
    else l = mid;
  }
}