void setup() {
  // Configure pins as outputs
  pinMode(13, OUTPUT); // Red
  pinMode(12, OUTPUT); // Yellow
  pinMode(11, OUTPUT); // Green
}

void loop() {
  // RED LIGHT
  digitalWrite(13, HIGH); // Turn on Red
  delay(3000);            // Wait 3 seconds
  digitalWrite(13, LOW);  // Turn off Red

  // YELLOW LIGHT
  digitalWrite(12, HIGH); // Turn on Yellow
  delay(2000);            // Wait 2 seconds
  digitalWrite(12, LOW);  // Turn off Yellow

  // GREEN LIGHT (This is the missing part)
  digitalWrite(11, HIGH); // Turn on Green
  delay(3000);            // Wait 3 seconds
  digitalWrite(11, LOW);  // Turn off Green
}