#include <Servo.h>
Servo myservo;
int pos = 0;
void setup() {
  // put your setup code here, to run once:
  myservo.attach(3);
}

void loop() {
  // put your main code here, to run repeatedly:
  for(pos=0;pos<180;pos++){
    myservo.write(pos);
    delay(10);
  }
  for(;pos>0;pos--){
    myservo.write(pos);
    delay(10);
  }


}