void setup() {
  pinMode(13, OUTPUT); // Red LED
  pinMode(12, OUTPUT); // Green LED
  pinMode(11, OUTPUT); // Yellow LED
  pinMode(10, OUTPUT); // Pedestrian crossing LED
  pinMode(9, OUTPUT);  // Left turn LED
}

void loop() {
  digitalWrite(13, LOW);
  digitalWrite(12, HIGH);
  digitalWrite(11, LOW);
  digitalWrite(10, HIGH);
  digitalWrite(9, HIGH);
  delay(4000);

  digitalWrite(13, LOW);
  digitalWrite(12, LOW);
  digitalWrite(11, HIGH);
  digitalWrite(10, LOW);
  digitalWrite(9, LOW);
  delay(3000);

  for (int i = 0; i < 10; i++) {
    digitalWrite(13, HIGH);
    digitalWrite(12, LOW);
    digitalWrite(11, LOW);
    digitalWrite(9, LOW);
    digitalWrite(10, i % 2);
    delay(500);
  }

  digitalWrite(13, HIGH);
  digitalWrite(12, LOW);
  digitalWrite(11, LOW);
  digitalWrite(10, LOW);
  digitalWrite(9, HIGH);
  delay(4000);

  digitalWrite(13, LOW);
  digitalWrite(12, HIGH);
  digitalWrite(11, LOW);
  digitalWrite(10, LOW);
  digitalWrite(9, LOW);
  delay(4000);
}