void setup() {
  pinMode(8, OUTPUT);
  pinMode(9, OUTPUT);
  pinMode(10, OUTPUT);
  pinMode(11, OUTPUT);

  // put your setup code here, to run once:

}

void loop() {
  digitalWrite(8,1);
  delay(3000);
  digitalWrite(8,0);
  digitalWrite(9,1);
  delay(1000);
  digitalWrite(9,0);
  digitalWrite(10,1);
  delay(3000);
  digitalWrite(10,0);
  digitalWrite(11,1);
  delay(1000);
  digitalWrite(11,0);
  
  // put your main code here, to run repeatedly:

}