void setup() {
pinMode(LED_BUILTIN, OUTPUT);
}
void loop() {
digitalWrite(LED_BUILTIN, HIGH);
delay(400);
digitalWrite(LED_BUILTIN, LOW);
delay(400);
digitalWrite(LED_BUILTIN, HIGH);
delay(50);
digitalWrite(LED_BUILTIN, LOW);
delay(400);
digitalWrite(LED_BUILTIN, HIGH);
delay(50);
digitalWrite(LED_BUILTIN, LOW);
delay(400);
digitalWrite(LED_BUILTIN, HIGH);
delay(50);
digitalWrite(LED_BUILTIN, LOW);
delay(1500);
}