int fun ( void );  //遵循1

int datax = 0;
int datay = 0;

int main ( void )
{
  int iz;

  datax = 1;
  datay = 2;
  iz = fun ( );

  return ( 0 );
}

int fun ( void )  //遵循2
{
  int temp;

  temp = 2 * datax + 3 * datay;

  return temp;
}