#include <Servo.h>

Servo myservo;

int pos = 0;

void setup() {
  pinMode(5, OUTPUT);
  pinMode(6, OUTPUT);
  pinMode(9, OUTPUT);
  pinMode(10, OUTPUT);
  pinMode(2, INPUT);
  pinMode(12, INPUT);
  pinMode(8, INPUT);
  pinMode(7, INPUT);
  myservo.attach(11);
}

void loop() {
  
  // Problem 1
  digitalWrite(5, HIGH);
  digitalWrite(6, HIGH);
  digitalWrite(9, HIGH);
  digitalWrite(10, HIGH);
  delay(500);

  digitalWrite(5, LOW);
  digitalWrite(6, LOW);
  digitalWrite(9, LOW);
  digitalWrite(10, LOW);
  delay(550);

  // Problem 2
  for (pos = 0; pos <= 45; pos += 1) { 
    myservo.write(pos);              
    delay(5);                       
  }
  for (pos = 45; pos >= 0; pos -= 1) { 
    myservo.write(pos);              
    delay(5);                       
  }

  // Problem 3
  while(digitalRead(2))
    {
    Serial.println("Button A is pushed.");
    Serial.println();
    }

    //Pushbutton B has been pressed
    while(digitalRead(12))
    {
    Serial.println("Button B is pushed.");
    Serial.println();
    }

    //Pushbutton C has been pressed
    while(digitalRead(8))
    {
    Serial.println("Button C is pushed.");
    Serial.println();
    }

    //Pushbutton D has been pressed
    while(digitalRead(7))
    {
    Serial.println("Button D is pushed.");
    Serial.println();
    }
}