void setup() {
  // put your setup code here, to run once:
  pinMode(3, OUTPUT); //red
  pinMode(4, OUTPUT); //yellow
  pinMode(5, OUTPUT); //green
}

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(3, HIGH);
  digitalWrite(4, LOW);
  digitalWrite(5, LOW);
  delay(5000);

  digitalWrite(3, LOW);
  digitalWrite(4, HIGH);
  digitalWrite(5, LOW);
  delay(500);

  digitalWrite(3, LOW);
  digitalWrite(4, LOW);
  digitalWrite(5, HIGH);
  delay(5000);
}