#define red 13
#define yellow 12
#define blue 11


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

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(yellow, HIGH);
  digitalWrite(red, LOW);
  digitalWrite(blue, LOW);
  delay(500);
  digitalWrite(yellow, LOW);
  digitalWrite(red, HIGH);
  digitalWrite(blue, LOW);
  delay(500);
  digitalWrite(yellow, LOW);
  digitalWrite(red, LOW);
  digitalWrite(blue, HIGH);
  delay(500);

}