void setup() {
  pinMode(13, OUTPUT);
   pinMode(12, OUTPUT);
   pinMode(11, OUTPUT);
   pinMode(10, OUTPUT);
  // put your setup code here, to run once:

}

void loop() {
 digitalWrite(13, HIGH);
 delay(500);
 digitalWrite(13, LOW);
 delay(500);
 
 digitalWrite(12, HIGH);
 delay(500);
 digitalWrite(12, LOW);
 delay(500);

  digitalWrite(11, HIGH);
 delay(500);
 digitalWrite(11, LOW);
 delay(500);

  digitalWrite(10, HIGH);
 delay(500);
 digitalWrite(10, LOW);
 delay(500);
  // put your main code here, to run repeatedly:

}