void setup() {
  for(int i = 11; i <= 13; i ++){
    pinMode(i, OUTPUT);
  }

}

void loop() {
  // put your main code here, to run repeatedly:
  for (int i = 11; i<= 13; i++){
    digitalWrite(i, HIGH);
    delay(250);
    digitalWrite(i, LOW);
    delay(250);
  }
  lampu_kuning(12);
  lampu_merah(11);
}

void lampu_kuning(int a){
  if(a == 12){
      for(int i = 0; i < 4; i++){
        digitalWrite(12, HIGH);
        delay(500);
        digitalWrite(12, LOW);
        delay(500);
      }
    }
}

void lampu_merah(int a){
  if(a == 11){
      for(int i = 0; i < 6; i++){
        digitalWrite(11, HIGH);
        delay(500);
        digitalWrite(11, LOW);
        delay(500);
      }
  }
}

void bersamaan()