int red = 13;
int green = 12;
int blue = 11;

void setup() {
  pinMode(13, OUTPUT);
  pinMode(12, OUTPUT);
  pinMode(11, OUTPUT);

  digitalWrite(13, LOW);
  digitalWrite(12, LOW);
  digitalWrite(11, LOW);

}

void loop() {

  digitalWrite(13, HIGH);
  delay(500);
  digitalWrite(13, LOW);
  delay(500);

  digitalWrite(12, HIGH);
  delay(500);
  digitalWrite(12, LOW);
  delay(500);

  digitalWrite(11, HIGH);
  delay(500);
  digitalWrite(11, LOW);
  delay(500);

}