#include <Servo.h>
Servo S;
const int button = 4;

int buttonstate = 0;

void setup() {
  S.attach(9);
  pinMode(button, INPUT);
  S.write(0);
}

void loop() {
  buttonstate = digitalRead(button);

  if(buttonstate == 1){
    S.write(180);
    delay(3000);
    S.write(0);
  }
}