int delay1 = 3000;
int delay2 = 1000;

void setup() {
  DDRB=B11111100;
  DDRB=B11111111;
}

void loop() {
  digitalWrite(13, HIGH);
  digitalWrite(2, HIGH);
  delay(delay1);
  digitalWrite(13, LOW);
  digitalWrite(2, LOW);

  digitalWrite(13, HIGH);
  digitalWrite(3, HIGH);
  delay(delay2);
  digitalWrite(13, LOW);
  digitalWrite(3, LOW);

  digitalWrite(11, HIGH);
  digitalWrite(4, HIGH);
  delay(delay1);
  digitalWrite(11, LOW);
  digitalWrite(4, LOW);

  digitalWrite(12, HIGH);
  digitalWrite(4, HIGH);
  delay(delay2);
  digitalWrite(12, LOW);
  digitalWrite(4, LOW);
}