void turn_around()
{
  OnRev(OUT_C); Wait(340);
  OnFwd(OUT_A+OUT_C);
}

task main()
{
  OnFwd(OUT_A+OUT_C);
  Wait(100);
  turn_around();
  Wait(200);
  turn_around();
  Wait(100);
  turn_around();
  Off(OUT_A+OUT_C);
}