#define LED_pin 2
#define LED_pin2 3
#define LED_pin3 4 
#define LED_pin4 5

void setup() {
  pinMode(LED_pin, OUTPUT);
  pinMode(LED_pin2, OUTPUT);
  pinMode(LED_pin3, OUTPUT);
  Serial.begin(9600);
}
void loop() {
  digitalWrite(LED_pin, HIGH);
  digitalWrite(LED_pin2, HIGH);
  digitalWrite(LED_pin3, HIGH);
  digitalWrite(LED_pin4, HIGH);
  Serial.println("4 LED's turns ON");
  delay(2000);
  digitalWrite(LED_pin, LOW);
  digitalWrite(LED_pin2, LOW);
  digitalWrite(LED_pin3, LOW);
  digitalWrite(LED_pin4, LOW);
  Serial.println("4 LED's turns OFF");
  delay(2000);
}