func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long N = 2e9;   long long sum(long long l, long long r) { return (l + r) * (r - l + 1) / 2; }   int main() {     long long n, H;     cin >> n >> H;     long long l = H, r = 2e9, ans = -1;     while (l <= r) {       long long mid = (l + r) >> 1;       if (n >= sum(H, mid) + sum(1, mid) - mid)         ans = mid, l = mid + 1;       else         r = mid - 1;     }     if (ans != -1) {       cout << 2 * ans - H +                   ((n - sum(H, ans) - sum(1, ans) + ans) + ans - 1) / ans            << endl;     } else {       l = 1, r = min(H, N);       while (l <= r) {         long long mid = (l + r) >> 1;         if (n >= sum(1, mid))           ans = mid, l = mid + 1;         else           r = mid - 1;       }       cout << ans + (n - sum(1, ans) + ans - 1) / ans << endl;     }     return 0;   }   