int ledPins[] = {2, 3, 4, 5, 6};  // Array to store LED pin numbers
void setup() {
  for (int i = 0; i < 5; i++) {
    pinMode(ledPins[i], OUTPUT);  // Set each pin as output
  }
}
void loop() {
  for (int i = 0; i < 5; i++) {
    digitalWrite(ledPins[i], HIGH);  // Turn on LED
    delay(500);                      // Wait 500ms
    digitalWrite(ledPins[i], LOW);   // Turn off LED
    delay(500);                      // Wait 500ms before next LED
  }
}