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


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

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(red, HIGH);
  digitalWrite(orange, LOW);
  digitalWrite(green, LOW);
  delay(1500);

  digitalWrite(red, LOW);
  digitalWrite(orange, HIGH);
  digitalWrite(green, LOW);
  delay(1500);

  digitalWrite(red, LOW);
  digitalWrite(orange, LOW);
  digitalWrite(green, HIGH);
  delay(1500);
}