task main(){

  SetSensorLowspeed(IN_4);

  int Distance = 0;

  for(int x = 0; x < 4; x ++ ){

    OnFwdSync(OUT_BC, 50, -100);

    Wait(950);

    Distance = SensorUS(IN_4);

    Coast(OUT_BC);

    NumOut(0, LCD_LINE1, (Distance));

    PlayTone(440, 100);

  }

}