void setup() {
  pinMode(13, OUTPUT);
}

void loop() {  
  int red = 13, yellow = 12, blue = 11;
  int i = 0;
  while (i < 10)
  {
    digitalWrite(red, HIGH);
    digitalWrite(yellow, LOW);
    digitalWrite(blue, LOW);
    delay(100);
    digitalWrite(red, LOW);
    digitalWrite(yellow, HIGH);
    digitalWrite(blue, LOW);
    delay(100);
    digitalWrite(red, LOW);
    digitalWrite(yellow, LOW);
    digitalWrite(blue, HIGH);
    delay(100);
    i++;
  }
  a();
}

void a()
{
  int red = 13, yellow = 12, blue = 11;
  digitalWrite(red, HIGH);
  digitalWrite(yellow, LOW);
  digitalWrite(blue, LOW);
  delay(3000);
  digitalWrite(red, LOW);
  digitalWrite(yellow, HIGH);
  digitalWrite(blue, LOW);
  delay(3000);
  digitalWrite(red, LOW);
  digitalWrite(yellow, LOW);
  digitalWrite(blue, HIGH);
  delay(3000);
}