int BIRU=8;
int MERAH=9;

void setup() {
  // put your setup code here, to run once:
pinMode(BIRU, OUTPUT);
pinMode(MERAH, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(BIRU,LOW);
  digitalWrite(MERAH ,LOW);
  delay((1000));
digitalWrite(BIRU, HIGH);
digitalWrite(MERAH,HIGH);
delay(1000);
digitalWrite(BIRU, LOW);
digitalWrite(MERAH, LOW);
delay(1000);
digitalWrite(BIRU,HIGH);
digitalWrite(MERAH ,LOW );
delay(1000);
digitalWrite(BIRU,LOW  );
digitalWrite(MERAH,HIGH);
delay(1000);

}