void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(25, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(27, OUTPUT);
  pinMode(17, OUTPUT);
  pinMode(12, OUTPUT);
  pinMode(18, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(25, HIGH);
  digitalWrite(4, HIGH);
  delay(15000);
  digitalWrite(25, LOW);
  digitalWrite(4, LOW);
  digitalWrite(27, HIGH);
  digitalWrite(17, HIGH);
  delay(5000);
  digitalWrite(27, LOW);
  digitalWrite(17, LOW);
  digitalWrite(12, HIGH);
  digitalWrite(18, HIGH);
  delay(15000);
  digitalWrite(12, LOW);
  digitalWrite(18, LOW);
  digitalWrite(27, HIGH);
  digitalWrite(17, HIGH);
  delay(5000);
  digitalWrite(27, LOW);
  digitalWrite(17, LOW);
  delay(10); // this speeds up the simulation
}