#define LED_PIN 12
#define KEY_PIN 9

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


}

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(LED_PIN, LOW);
  delay(500);
  digitalWrite(LED_PIN, HIGH);
  delay(500);

  if (digitalRead(KEY_PIN) == LOW){
    digitalWrite(LED_BUILTIN, HIGH);
  } else {
    digitalWrite(LED_BUILTIN, LOW);
  }

}