__code print_factorial(int prod)
{
  printf("factorial = %d\n",prod);
  exit(0);
}
__code factorial0(int prod, int x)
{
  if ( x >= 1) {
    goto factorial0(prod*x, x-1);
  }else{
    goto print_factorial(prod);
  }
}
__code factorial(int x)
{
  goto factorial0(1, x);
}