// Define the LED pins
const int ledPins[] = {0, 1, 2, 3, 4, 5};  // Pins connected to LEDs

void setup() {
  // Initialize the LED pins as outputs
  for (int i = 0; i < 6; i++) {
    pinMode(ledPins[i], OUTPUT);
  }
}

void loop() {
  // Chase the LEDs forward
  for (int i = 0; i < 6; i++) {
    digitalWrite(ledPins[i], HIGH);
    delay(100);
    digitalWrite(ledPins[i], LOW);
  }

  // Chase the LEDs backward
  for (int i = 4; i > 0; i--) {
    digitalWrite(ledPins[i], HIGH);
    delay(100);
    digitalWrite(ledPins[i], LOW);
  }
}