int merah = 12;
int kuning = 11;
int hijau = 10;

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

pinMode(11, OUTPUT);

pinMode(10, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(merah, HIGH);
delay(2000);

digitalWrite(merah, LOW);

digitalWrite(kuning, HIGH);
delay(3000);

digitalWrite(kuning, LOW);

digitalWrite(hijau, HIGH);
delay(4000);

digitalWrite(hijau, LOW);
}