void setup() {
   pinMode(13, OUTPUT);
   pinMode(12, OUTPUT);
   pinMode(11, OUTPUT);
}

void loop() {
   digitalWrite(13, HIGH); 

   delay(500);

   digitalWrite(13, LOW); 

   delay(500);
     digitalWrite(12, HIGH); 

   delay(700);

   digitalWrite(12, LOW); 

   delay(700);
      digitalWrite(11, HIGH); 

   delay(900);

   digitalWrite(11, LOW); 

   delay(700);
}