int led1 = 13;
int led2 = 12;
int led3 = 11;

void setup() {
  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(led3, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  digitalWrite(led1, HIGH);
  digitalWrite(led2, LOW);
  digitalWrite(led3, LOW);
  Serial.println("Red Signal");
  delay(5000);
  digitalWrite(led1, LOW);
  digitalWrite(led2, HIGH);
  Serial.println("Yellow Signal");
  delay(500);
  digitalWrite(led2, LOW);
  digitalWrite(led3, HIGH);
  Serial.println("Green Signal");
  delay(3000);
}