void setup() {
  pinMode(13,OUTPUT); //Set pin 13 as output
  pinMode(12,OUTPUT); //Set pin 12 as output
  pinMode(11,OUTPUT); //Set pin 11 as output

}

void loop() {
  digitalWrite(13, HIGH);
  digitalWrite(12, LOW);
  digitalWrite(11, LOW);
  delay(1000);

  digitalWrite(12, HIGH);
  digitalWrite(13, LOW);
  digitalWrite(11, LOW);
  delay(1000);

  digitalWrite(11, HIGH);
  digitalWrite(12, LOW);
  digitalWrite(13, LOW);
  delay(1000);

  digitalWrite(11, LOW);
  digitalWrite(12, LOW);
  digitalWrite(13, LOW);
  delay(1000);

  digitalWrite(11, HIGH);
  digitalWrite(12, HIGH);
  digitalWrite(13, HIGH);
  delay(1000);

  digitalWrite(11, LOW);
  digitalWrite(12, LOW);
  digitalWrite(13, LOW);
  delay(1000);

}