#include using namespace std; #define For(i, a, b) for(int i = (a); i < (b); i++) #define rep(i, n) For(i, 0, n) #define rFor(i, a, b) for(int i = (a); i >= (b); i--) #define ALL(v) (v).begin(), (v).end() #define rALL(v) (v).rbegin(), (v).rend() using lint = long long; using ld = long double; int INF = 2000000000; lint LINF = 1000000000000000000; int main() { ios::sync_with_stdio(false); cin.tie(nullptr); auto ask = [](int x) -> int { cout << x << "\n"; cout.flush(); int r; cin >> r; return r; }; int l = 0, r = 1000000010; while (r - l > 1) { int mid = (l + r) / 2; if (ask(mid)) { return 0; } else { r = mid; } } }