#define verde 5
#define amarillo 4
#define rojo 2

void setup(){
  pinMode(verde, OUTPUT);
  pinMode(amarillo, OUTPUT);
  pinMode(rojo, OUTPUT);
}

void loop(){

  digitalWrite(verde, HIGH);
  digitalWrite(amarillo, LOW);
  digitalWrite(rojo, LOW);
  delay(12000);
   
  digitalWrite(verde, LOW);
  digitalWrite(amarillo, HIGH);
  digitalWrite(rojo, LOW);
  delay(3000);
  digitalWrite(amarillo, LOW);
  delay(500);
  digitalWrite(amarillo, HIGH);
  delay(500);
  digitalWrite(amarillo, LOW);
  delay(500);
  digitalWrite(amarillo, HIGH);
  delay(500);
  digitalWrite(amarillo, LOW);
  delay(500);
  digitalWrite(amarillo, HIGH);
  delay(500);

  digitalWrite(verde, LOW);
  digitalWrite(amarillo, LOW);
  digitalWrite(rojo, HIGH);
  delay(16000);
}