void setup() {
  // put your setup code here, to run once:
  pinMode(21, OUTPUT);  //Pin 18 (LED hijau) sebagai output digital
  pinMode(18, OUTPUT);  //Pin 18 (LED merah) sebagai output digital
  pinMode(19, OUTPUT);  //Pin 18 (LED kuning) sebagai output digital
}

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(21, HIGH); //ON LED Red
  delay(9000);
   digitalWrite(21, LOW);  //OFF LED Red
  delay(100);

  digitalWrite(19, HIGH); //ON LED Yellow
  delay(90);
  digitalWrite(19, LOW);  //OFF LED Yellow
  delay(90);

  digitalWrite(18, HIGH); //ON LED Green
  delay(7000);
  digitalWrite(18, LOW);  //OFF LED Green
  delay(50);

  digitalWrite(19, HIGH); //ON LED Yellow
  delay(90);
  digitalWrite(19, LOW);  //OFF LED Yellow
  delay(90);
  
}