// Pin assignments
const int ledPins[] = {0, 1, 2, 3, 4, 6, 7, 8, 9, 10};

void setup() {
  // Set LED pins as OUTPUT
  for (int i = 0; i < 10; i++) {
    pinMode(ledPins[i], OUTPUT);
  }
}

void loop() {
  // Blink the LEDs in sequence
  for (int i = 0; i < 10; i++) {
    digitalWrite(ledPins[i], HIGH);   // Turn LED on
    delay(100);                        // Wait for 500 milliseconds
    digitalWrite(ledPins[i], LOW);    // Turn LED off
    delay(50);                        // Wait for 100 milliseconds
  }
  for (int i=0;i>10;i--) {
    digitalWrite(ledPins[i], HIGH);
    delay(100);
    digitalWrite(ledPins[i], LOW);
    delay(50);
      }
}