void setup() {
  pinMode(4, OUTPUT);
  pinMode(2, OUTPUT);
  pinMode(15, OUTPUT);
}

void loop() {
  digitalWrite(15, HIGH);
  delay(10000);
  digitalWrite(15, LOW);
  digitalWrite(2, 1);
  delay(3000);
  digitalWrite(2, 0);
  digitalWrite(4, HIGH);
  delay(10000); //10s
  digitalWrite(4, LOW);
}