int Ledrojo = 3;
int Ledamarillo = 4;
int Ledverde = 5;

void setup() {

  pinMode(Ledrojo,OUTPUT);
  pinMode(Ledamarillo,OUTPUT);
  pinMode(Ledverde,OUTPUT);
   
}

void loop() {
  
  digitalWrite(Ledrojo,LOW);
  digitalWrite(Ledamarillo,LOW);
  digitalWrite(Ledverde,HIGH);    
  delay(6000);
  
  digitalWrite(Ledamarillo,HIGH);
  digitalWrite(Ledverde,LOW);    
  delay(2000);
  
  digitalWrite(Ledrojo,HIGH);
  digitalWrite(Ledamarillo,LOW);
  delay(6000);
          
}