void setup() {
  pinMode(1, OUTPUT) ;
  pinMode(2, OUTPUT);
  pinMode(3,OUTPUT);

}

void loop() {
  digitalWrite(1, HIGH);
  delay(50);
  digitalWrite(1, LOW);
  delay(50);
  digitalWrite(2, HIGH);
  delay(50);
  digitalWrite(2, LOW);
  delay(50);
  digitalWrite(3, HIGH);
  delay(50);
  digitalWrite(3, LOW);
  delay(50);
  digitalWrite(13, HIGH);
  delay(100);
  digitalWrite(13, LOW);
  delay(100);

}