void setup() {
pinMode(8, OUTPUT);
pinMode(9, OUTPUT);
pinMode(12, OUTPUT);
pinMode(13, OUTPUT);

}

void loop() {
digitalWrite(8, HIGH);
delay(1000);
digitalWrite(8,LOW);
delay(1000);
digitalWrite(9,HIGH);
delay(500);
digitalWrite(9,LOW);
delay(500);
digitalWrite(12,HIGH);
delay(500);
digitalWrite(12, LOW);
delay(500);
digitalWrite(13, HIGH);
delay(500);
digitalWrite(13,LOW);
delay(500);
}