#include "library.h"

void main()
{ const double A = 1;
  const double B = -7;
  const double C = 3;
  const double x = (-B - sqrt(B*B - 4*A*C)) / (2*A);

  print("x = ");
  print(x);
  new_line();

  print("This should be almost zero: ");
  print(A*x*x + B*x + C);
  new_line(); }