#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; #define fst first #define scd second #define PB push_back #define MP make_pair #define size(a) ((int)a.size()) #define int long long #define all(a) a.begin(),a.end() #define rall(a) a.rbegin(),a.rend() #define omajinai ios::sync_with_stdio(false);cin.tie(0) typedef long long ll; typedef long double ld; typedef vector vi; typedef vector vvi; typedef pair pii; typedef vector vpii; templateT& max(T&a,T&b){if(a>=b)return a;return b;} templateT& min(T&a,T&b){if(abool chmax(T&a,T b){if(abool chmin(T&a,T b){if(a>b){a=b;return true;}return false;} templateT get(){T a;cin>>a;return a;} templateT rev(T a){reverse(all(a));return a;} templatevector&sort(vector&a){sort(all(a));return a;} const int inf = 1e9; const ll linf = 3e18; const double eps = 1e-9; signed main() { int lb = 0, ub = 1e9; for (int i = 0; i < 60; ++i) { if (ub - lb <= 3) break; int mid = (lb + ub) / 2; cout << "? " << mid << endl; int res; cin >> res; if (res == 0) { cout << "! " << mid << endl; return 0; } else if (res == -1) { ub = mid; lb = min(lb - 1, max(lb, 0ll)); } else if (res == 1) { lb = mid; } } lb -= 5; for (int i = 0; i < 10; ++i) { cout << "? " << lb << endl; int res; cin >> res; if (res == 0) { cout << "! " << lb << endl; return 0; } } }