int ledMerah = 13;
int ledKuning = 12;
int ledIjo = 7;
int B = 6;

void setup() {
pinMode (ledMerah, OUTPUT);
pinMode(ledKuning, OUTPUT);
pinMode(ledIjo, OUTPUT);
pinMode(B, OUTPUT);
digitalWrite (ledMerah, HIGH);
digitalWrite(ledKuning, HIGH);
digitalWrite(ledIjo, HIGH);
digitalWrite(B, HIGH);
delay (2000);
}

void loop() {
digitalWrite (ledMerah, HIGH);
digitalWrite(ledKuning, LOW);
digitalWrite(ledIjo, LOW);
delay (2000);
digitalWrite (ledMerah, LOW);
digitalWrite(ledKuning, HIGH);
digitalWrite(ledIjo, LOW);
delay (2000);
digitalWrite (ledMerah, LOW);
digitalWrite(ledKuning, LOW);
digitalWrite(ledIjo, HIGH);
tone(B, 2000, 500);
delay (2000);
}