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(4,HIGH);
    delay(1000);
    digitalWrite(27,LOW);
    digitalWrite(4, LOW);
    delay(1000);
    digitalWrite(14, HIGH);
    digitalWrite(5, HIGH);
    delay(1000);
    digitalWrite(14, LOW);
    digitalWrite(5, LOW);
    delay(1000);
    digitalWrite(12, HIGH);
    digitalWrite(21, HIGH);
    delay(1000);
    digitalWrite(12, LOW);
    digitalWrite(21, LOW);
    delay(1000);
}