func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 1000 + 11;   int sdis(int x, int y, int xx, int yy) {     int dx = x - xx;     int dy = y - yy;     return dx * dx + dy * dy;   }   int main() {     int ax, ay, ar, bx, by, br;     while (cin >> ax >> ay >> ar >> bx >> by >> br) {       int ds = sdis(ax, ay, bx, by);       if ((ar + br) * (ar + br) <= ds) {         printf( %.10lf n , (sqrt(ds + 0.0) - ar - br) * 0.5);       } else if (ds <= (ar - br) * (ar - br)) {         printf( %.10lf n , (abs(ar - br) - sqrt(ds + 0.0)) * 0.5);       } else {         printf( %.10lf n , 0.0);       }     }   }   