void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(2, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(13, OUTPUT);
  pinMode(14, OUTPUT);
  pinMode(15, OUTPUT);
  pinMode(18, OUTPUT);
  pinMode(19, OUTPUT);
  pinMode(21, OUTPUT);
}

void loop() {
  //ledurile sunt aprinse constant
digitalWrite(2, HIGH);
digitalWrite(4, HIGH);
digitalWrite(13, HIGH);
delay(500);

/*ledurile sunt aprinse pe rand
digitalWrite(2, HIGH);
delay(500);
digitalWrite(2, LOW);

digitalWrite(4, HIGH);
delay(500);
digitalWrite(4, LOW);

digitalWrite(13, HIGH);
delay(500);
digitalWrite(13, LOW);*/
}