int led;
void setup() {
  for(led = 2; led <= 11; led++)
    pinMode(led, OUTPUT);
}

void loop() {
  for(led = 2; led <= 11; led++){
    digitalWrite(led, HIGH);
    delay(500);
  }
  for(led = 2; led <= 11; led++){
    digitalWrite(led, LOW);
    delay(500);
  }
  delay(500);

  for(led = 2; led <= 11; led++){
    digitalWrite(led, HIGH);
    delay(500);
    digitalWrite(led, LOW);
  }
  delay(500);

  for(led = 2; led <= 11; led++){
    digitalWrite(led, HIGH);
    delay(100);
    digitalWrite(led, LOW);
  }
  for(led = 11; led >= 2; led--){
    digitalWrite(led, HIGH);
    delay(100);
    digitalWrite(led, LOW);
  }
}