const int redLedPin = 10;
const int firstYellowLedPin = 11;
const int secondYellowLedPin = 12;
const int greenLedPin = 13;

void setup() {
  // Initialize the LED pins as outputs
  pinMode(redLedPin, OUTPUT);
  pinMode(firstYellowLedPin, OUTPUT);
  pinMode(secondYellowLedPin, OUTPUT);
  pinMode(greenLedPin, OUTPUT);
}

void loop() {
  
  digitalWrite(redLedPin, LOW);
  digitalWrite(firstYellowLedPin, LOW);
  digitalWrite(secondYellowLedPin, LOW);
  digitalWrite(greenLedPin, LOW);
  
  delay(1000); 
  digitalWrite(redLedPin, HIGH);
  delay(1000); 
  digitalWrite(redLedPin, LOW);
  delay(1000);
  digitalWrite(firstYellowLedPin, HIGH);
  digitalWrite(redLedPin, HIGH);
  delay(1000);
   digitalWrite(firstYellowLedPin, LOW);
  digitalWrite(redLedPin, LOW);
  delay(1000); 
  digitalWrite(secondYellowLedPin, HIGH);
  digitalWrite(firstYellowLedPin, HIGH);
  digitalWrite(redLedPin, HIGH);
  delay(1000); 
  digitalWrite(secondYellowLedPin, LOW);
  digitalWrite(firstYellowLedPin, LOW);
  digitalWrite(redLedPin, LOW);
  delay(1000);
  digitalWrite(greenLedPin, HIGH);
  digitalWrite(secondYellowLedPin, HIGH);
  digitalWrite(firstYellowLedPin, HIGH);
  digitalWrite(redLedPin, HIGH);
  delay(2000); 
  digitalWrite(redLedPin, LOW);
  digitalWrite(firstYellowLedPin, LOW);
  digitalWrite(secondYellowLedPin, LOW);
  digitalWrite(greenLedPin, LOW);
  delay(2000); 
}