void setup() 
{
  // put your setup code here, to run once:
  Serial.begin(115200);
  // traffic light 1
  pinMode(27, OUTPUT);
  pinMode(14, OUTPUT);
  pinMode(12, OUTPUT);
  //Traffic light 2
  pinMode(21, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(5, OUTPUT);
}

void loop()
{
  digitalWrite(27,HIGH);
  digitalWrite(5,HIGH);
  delay(1000);

  digitalWrite(27,LOW);
  digitalWrite(5, LOW);
  delay(1000);
  
   digitalWrite(14, HIGH);
  digitalWrite(4, HIGH);
  delay(1000);
  
  digitalWrite(14, LOW);
  digitalWrite(4, LOW);
  delay(1000);

  digitalWrite(12, HIGH);
  digitalWrite(21, HIGH);
  delay(1000);

  digitalWrite(12, LOW);
  digitalWrite(21, LOW);
  delay(1000);
}