#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; #define REP(i,a,b) for(int i=a;i<(int)b;i++) #define rep(i,n) REP(i,0,n) typedef long long ll; int ask(int Y){cout << "? " << Y << endl;int res;cin >> res;return res;} int res = 1e9+1; int solve(int curr, int depth = 0) { if(depth == 100) { return depth; } switch(ask(res)) { case -1: res -= curr; res --; break; case 1: res += curr; res --; break; case 0: return depth; } return solve(curr/2, depth+1); } int main(){ { auto j = ask(50); if(j == 0) { cout << "! 50\n"; return 0; } else if(j == -1) { auto depth = solve((res = 25) / 2); cout << "! " << res + depth + 1 << endl; return 0; } } auto depth = solve((res = 1e9)/2, 1); cout << "! " << res + depth << endl; return 0; }