// Include required libraries
#include <Arduino.h>

// Define the pins for the LEDs
const int ledPins[] = {4, 0, 2, 15}; // Change pins as per your setup

// Define the time interval for blinking
const int blinkInterval = 500; // Blink interval in milliseconds

void setup() {
  // Set all LED pins as output
  for (int i = 0; i < 4; i++) {
    pinMode(ledPins[i], OUTPUT);
  }
}

void loop() {
  // Pattern A: All LEDs off
  allOff();

  delay(blinkInterval);

  // Pattern B: All LEDs on
  allOn();

  delay(blinkInterval);
}

void allOff() {
  // Turn off all LEDs
  for (int i = 0; i < 4; i++) {
    digitalWrite(ledPins[i], LOW);
  }
}

void allOn() {
  // Turn on all LEDs
  for (int i = 0; i < 4; i++) {
    digitalWrite(ledPins[i], HIGH);
  }
}