int ledmerah = 13;
int ledkuning = 12;
int ledhijau = 11;

void setup() {
  pinMode(ledmerah, OUTPUT);
  pinMode(ledkuning, OUTPUT);
  pinMode(ledhijau, OUTPUT);
  }

void loop() {
  digitalWrite(ledmerah, HIGH);
  delay(500);
  digitalWrite(ledmerah, LOW);
  digitalWrite(ledkuning, HIGH);
  digitalWrite(ledhijau, HIGH);
  }