#define LED1 2
#define LED2 4
#define LED3 5

void setup(){
  pinMode(LED1, OUTPUT);
  pinMode(LED2, OUTPUT);
  pinMode(LED3, OUTPUT);

}
void loop(){
  digitalWrite(LED1, HIGH);
  delay(500);
  digitalWrite(LED2, HIGH);
  delay(1000);
  digitalWrite(LED3, HIGH);
  delay(1500);
  digitalWrite(LED1, LOW);
  delay(500);
  digitalWrite(LED2, LOW);
  delay(1000);
  digitalWrite(LED3, LOW);
  delay(1500);
}