void setup() {
  // put your setup code here, to run once:
  DDRD = B11111111; //pinMode(X, OUTPUT);
  DDRB = B00000011;
}

void loop() {
  // put your main code here, to run repeatedly:
  PORTD = B10101010;
  PORTB = B00000011;
  delay(1);
  PORTD = B01010101;
  PORTB = B00000000;
  delay(1);
}