func_code_string: #include <bits/stdc++.h>   using namespace std;   const double pi = acos(-1.0);   const int inf = 0x3f3f3f3f;   const double eps = 1e-10;   const long long INF = (1LL << 60);   int main() {     int a, b;     scanf( %d%d , &a, &b);     if (a == b) {       printf( %d n , a);       return 0;     }     double ans = -1;     if (a >= b) {       int k = (int)floor((a * 1.0 / b - 1) / 2);       ans = (a - b) * 1.0 / (2 * k);       ans = min(ans, (a + b) * 1.0 / (2 * k + 2));     }     printf( %0.12f n , ans);     return 0;   }   