#include <Servo.h>

Servo myServo;

void setup() {
  // put your setup code here, to run once:
myServo.attach(9);
}

void loop() {
  // put your main code here, to run repeatedly:
myServo.write(180);
delay(2000);

myServo.write(90);
delay(2000);

myServo.write(0);
delay(2000);

myServo.write(90);
delay(2000);
}