void setup()
{
  pinMode(13,OUTPUT);
  pinMode(15,OUTPUT);
  pinMode(18,OUTPUT);
  pinMode(5,OUTPUT);
}

  void loop()
{
  digitalWrite(13,HIGH);
  digitalWrite(15,LOW);
  digitalWrite(18,LOW);
  digitalWrite(5,LOW);
  delay(1000);

  digitalWrite(13,LOW);
  digitalWrite(15,HIGH);
  digitalWrite(18,LOW);
  digitalWrite(5,LOW);
  delay(1000);

  digitalWrite(13,LOW);
  digitalWrite(15,LOW);
  digitalWrite(18,HIGH);
  digitalWrite(5,LOW);
  delay(1000);

  digitalWrite(13,LOW);
  digitalWrite(15,LOW);
  digitalWrite(18,LOW);
  digitalWrite(5,HIGH);
  delay(1000);
}