func_code_string: #include <bits/stdc++.h>   using namespace std;   const int INF = 2000000009;   const int Max = 1000007;   const double PI = acos(-1.0);   double binSearch(double p, double b) {     int low = 0, high = INF, k;     double x;     while (low <= high) {       k = (low + high) / 2;       x = p / (2.0 * k);       if (x < b)         high = k - 1;       else if (x == b)         return x;       else         low = k + 1;     }     x = p / (2 * high);     if (x < b) x = p / (2 * low);     return x;   }   int main() {     int i, j, k, l, temp, t, n, m, caseno = 0, ans;     string str;     double a, b, x;     while (cin >> a >> b) {       if (b > a) {         cout << -1 << endl;         continue;       }       x = binSearch((a + b), b);       printf( %.10lf n , x);     }     return 0;   }   