#define LED_COUNT 8 
#define BUTTON_PIN 2 
int leds[LED_COUNT] = {3, 4, 5, 6, 7, 8, 9, 10}; 
bool ledState = false; 
bool lastButtonState = LOW; 
unsigned long lastDebounceTime = 0; 
unsigned long debounceDelay = 50; 

void setup() {
  for (int i = 0; i < LED_COUNT; i++) {
    pinMode(leds[i], OUTPUT); 
    digitalWrite(leds[i], LOW); }
  pinMode(BUTTON_PIN, INPUT); 
}

void loop() {
  bool buttonState = digitalRead(BUTTON_PIN);
  if (buttonState != lastButtonState) {
    lastDebounceTime = millis();
  }

  if ((millis() - lastDebounceTime) > debounceDelay) {
    if (buttonState != ledState) {
      ledState = buttonState;
      if (ledState == HIGH) {
        for (int i = 0; i < LED_COUNT; i++) {
          digitalWrite(leds[i], HIGH);
          delay(100); 
        }
        for (int i = LED_COUNT - 1; i >= 0; i--) {
          digitalWrite(leds[i], LOW); 
          delay(100);
        }
      }
    }
  }

  lastButtonState = buttonState;
}