void setup() {
  // put your setup code here, to run once:
pinMode(2, OUTPUT);

pinMode(3, OUTPUT);

pinMode(4, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(2, HIGH);
delay(500);

digitalWrite(2, LOW);
delay(500);

digitalWrite(4, HIGH);
delay(500);

digitalWrite(4, LOW);
delay(500);

digitalWrite(3, HIGH);
delay(300);

digitalWrite(3, LOW);
delay(300);

digitalWrite(3, HIGH);
delay(300);

digitalWrite(3, LOW);
delay(300);

digitalWrite(2, HIGH);
digitalWrite(4, HIGH);
delay(300);

digitalWrite(2, LOW);
digitalWrite(4, LOW);
delay(500);
}