#define LED 25
unsigned long last_time = 0;
unsigned long last_time1 = 0;
int count = 0;
void setup() {
  pinMode(2, OUTPUT);
  pinMode(LED, OUTPUT);
}
void loop() {
  if ( millis() - last_time > 500) {
    digitalWrite(2, !digitalRead(2));
    last_time = millis();
  }
  if ( millis() - last_time1 >= 500) {
    last_time1 = millis();
    if ((count == 0 ) || (count == 1) ||(count == 4 ) || (count == 5)||(count == 8 ) || (count == 9)||(count == 14 )||(count == 16 )||(count == 18 )||(count == 20 )||(count == 22 )||(count == 24 )) {
      digitalWrite(LED, HIGH);
    }
    else if ((count == 2 ) || (count == 3)||(count == 6 )|| (count == 7)||(count == 10 )|| (count == 11)||(count == 12 ) || (count == 13)||(count == 15 )||(count == 17 )||(count == 19 )||(count == 21 )||(count == 23 )||(count == 25 )||(count == 26 )||(count == 27 )||(count == 28 )) {
      digitalWrite(LED, LOW);
    }
    count++;
    if(count>=29){
      count = 0 ;
    }
    
  }

}