void setup() {
  // put your setup code here, to run once:
pinMode(3, OUTPUT);
pinMode(4, OUTPUT);
pinMode(5, OUTPUT);
pinMode(6, OUTPUT);
pinMode(7, OUTPUT);
pinMode(8, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(3, 1);
digitalWrite(8, 1);
delay(3000);

digitalWrite(8, 0);
digitalWrite(7, 1);
delay(500);

digitalWrite(3, 0);
digitalWrite(7, 0);
digitalWrite(5, 1);
digitalWrite(6, 1);
delay(3000);

digitalWrite(5, 0);
digitalWrite(4, 1);
delay(500);

digitalWrite(4, 0);
digitalWrite(6, 0);
}