const int redled = 2;
const int yellowled = 3;
const int greenled = 4;
const int pushbutton = 5;

int buttonState;

void setup() {
  // put your setup code here, to run once:
pinMode(redled, OUTPUT);
pinMode(yellowled, OUTPUT);
pinMode(greenled, OUTPUT);
pinMode(pushbutton, INPUT);
Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
buttonState = digitalRead(pushbutton);
if (buttonState == LOW) {
  Serial.println("Button pressed");

  digitalWrite(redled, HIGH);
  delay(500);
  digitalWrite(redled, LOW);

  digitalWrite(yellowled, HIGH);
  delay(500);
  digitalWrite(yellowled, LOW);

  digitalWrite(greenled, HIGH);
  delay(500);
  digitalWrite(greenled, LOW);
}
else {
  Serial.println("button not pressed");

  digitalWrite(redled, HIGH);
  digitalWrite(yellowled, HIGH);
  digitalWrite(greenled, HIGH);
  delay(3000);

  for (int i = 0; i < 3; i++){
    digitalWrite(redled, HIGH);
    digitalWrite(yellowled, HIGH);
    digitalWrite(greenled, HIGH);
    delay(500);

    digitalWrite(redled, LOW);
    digitalWrite(yellowled, LOW);
    digitalWrite(greenled, LOW);
    delay(500);
  }
  }
}