constexpr uint8_t LedPins[] {4, 5, 13, 14, 15, 18, 21, 22, 33};
constexpr uint32_t BlinkTime {1000};

void setup()
{
  for (auto &LedPin : LedPins) pinMode(LedPin, OUTPUT);
}
void loop()
{
  for (auto &LedPin : LedPins) digitalWrite(LedPin, digitalRead(LedPin) ? LOW : HIGH);
  delay(BlinkTime);
}