#define LED_PIN 13 // Define a constant for the LED pin

void setup() {
  pinMode(LED_PIN, OUTPUT); // Set LED_PIN (pin 13) as an output
}

void loop() {
  digitalWrite(LED_PIN, HIGH); // Turn ON the LED connected to LED_PIN
  delay(1000); // Wait for 1000 milliseconds (1 second)
  
  digitalWrite(LED_PIN, LOW); // Turn OFF the LED connected to LED_PIN
  delay(1000); // Wait for 1000 milliseconds (1 second)
}