double f(double a, double b, double c) {
double r2111418 = a;
double r2111419 = b;
double r2111420 = r2111418 + r2111419;
double r2111421 = c;
double r2111422 = r2111420 + r2111421;
double r2111423 = 2.0;
double r2111424 = r2111422 / r2111423;
double r2111425 = r2111424 - r2111418;
double r2111426 = r2111424 * r2111425;
double r2111427 = r2111424 - r2111419;
double r2111428 = r2111426 * r2111427;
double r2111429 = r2111424 - r2111421;
double r2111430 = r2111428 * r2111429;
double r2111431 = sqrt(r2111430);
return r2111431;
}