/* Problem URL: https://codeforces.com/contest/2149/problem/F */ #include #include #include using namespace std; using namespace __gnu_pbds; template > using ordered_set = tree; #define V vector #define rmin(a, b) a = min(a, b) #define rmax(a, b) a = max(a, b) #define rep(i, lim) for (int i = 0; i < (lim); i++) #define nrep(i, s, lim) for (int i = s; i < (lim); i++) #define repv(i, v) for (auto &i : (v)) #define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; } #define sortv(v) sort(v.begin(), v.end()) #define all(v) (v).begin(), (v).end() using vi = vector; using vvi = vector; using vvvi = vector; using vvvvi = vector; using ll = long long; using vl = vector; using vvl = vector; using vvvl = vector; using vvvvl = vector; template auto operator<<(ostream &os, const vector &vec)->ostream& { os << vec[0]; for (size_t i = 1; i < vec.size(); i++) { os << ' ' << vec[i]; } os << '\n'; return os; } template auto operator>>(istream &is, vector &vec)->istream& { for (auto &i : vec) { is >> i; } return is; } template auto operator<<(ostream &os, const vector> &vec)->ostream& { for (auto &i : vec) { os << i[0]; for (size_t j = 1; j < i.size(); j++) { os << ' ' << i[j]; } os << '\n'; } return os; } template auto operator>>(istream &is, vector> &vec)->istream& { for (auto &i : vec) { for (auto &j : i) { is >> j; } } return is; } int main() { ios::sync_with_stdio(false); cin.tie(nullptr); int t; cin >> t; while (t--) { ll h, d; cin >> h >> d; ll add = 0; if (h == 1) { add = 1; } else { h--; } ll low = 0; ll high = d - 1; ll ans = d; while (low <= high) { ll mid = (high + low) >> 1; ll div = d / (mid + 1); ll rem = d % (mid + 1); ll tmp = (div * (div + 1) / 2) * (mid - rem + 1) + ((div + 1) * (div + 2) / 2) * rem - mid; if (tmp <= h) { ans = mid; high = mid - 1; continue; } low = mid + 1; }; cout << ans + d + add << '\n'; } }