int fun ( int p );

int main ( void )
{
  int x = 1, y = 2, z = 3;
  int r;

  y = y + x;
  x++;            //遵循1

  y++;            //遵循2
  z = z + y;

  z--;            //遵循3
  z = fun ( z );

  r = fun ( z );
  z--;            //遵循4

  return ( 0 );
}

int fun ( int p )
{
  int ret;

  ret = 2 * p;
  
  return ret;
}