func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     long long int a, b, x, y, aa;     scanf( %I64d %I64d , &x, &y);     if (y > x) {       printf( -1 n );       return 0;     }     a = x / y;     if ((x % y) && (a % 2)) a++;     if (!(a % 2))       aa = a - 1;     else       aa = a;     double cc = (double)(x - aa * y);     double c = cc / (double)a;     double res = y + c;     printf( %0.11lf n , res);     return 0;   }   