int pinExtIzq=13;
int pinExtDer=8;
int pinMedIzq=12;
int pinMedDer=9;
int pinIntIzq=11;
int pinIntDer=10;
void setup() {
  pinMode(pinExtIzq, OUTPUT); 
  pinMode(pinExtDer, OUTPUT); 
  pinMode(pinMedIzq, OUTPUT); 
  pinMode(pinMedDer, OUTPUT); 
  pinMode(pinIntDer, OUTPUT); 
  pinMode(pinIntIzq, OUTPUT); 
}

void loop() {
  digitalWrite(pinExtIzq, HIGH); 
  delay(1000); 
  digitalWrite(pinExtDer, HIGH); 
  delay(1000);
  digitalWrite(pinMedIzq, HIGH); 
  delay(1000); 
  digitalWrite(pinMedDer, HIGH); 
  delay(1000);
  digitalWrite(pinIntIzq, HIGH); 
  delay(1000); 
  digitalWrite(pinIntDer, HIGH); 
  delay(1000);
  digitalWrite(pinIntDer, LOW); 
  delay(1000);
  digitalWrite(pinIntIzq, LOW); 
  delay(1000);
  digitalWrite(pinMedDer, LOW); 
  delay(1000);
  digitalWrite(pinMedIzq, LOW); 
  delay(1000);
  digitalWrite(pinExtDer, LOW); 
  delay(1000);
  digitalWrite(pinExtIzq, LOW); 
  delay(1000);
}