#include using namespace std; using ll = long long; using ld = long double; using V = vector; using VV = vector; using VVV = vector; using VVVV = vector; using VVVVV = vector; using VVVVVV = vector; using VS = vector; using VB = vector; using VVB = vector; using P = pair; using M = map; using Q = queue; using PQ = priority_queue; using PQG = priority_queue>; using S = set; using VP = vector

; 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 templatebool chmin(T&a, const T&b){if(a>b){a=b;return true;}return false;} templatebool chmax(T&a, const T&b){if(avoid Vin(vector&a){rep(i,(int)a.size())cin>>a[i];} templatevoid VVin(vector>&a){rep(i,(ll)a.size())Vin(a[i]);} templatevoid Vout(const vector&a){rep(i,(ll)a.size()-1)cout<void Voutl(const vector&a){rep(i,(ll)a.size())cout<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\n", a, b); } 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; } }