const int LED = 4;
const int pinLED[LED] = {8, 9, 10, 11};

void setup() {
  // put your setup code here, to run once:
  for(int i=0; i<4; i++){
    pinMode(pinLED[i], OUTPUT);
  }
}

void loop() {
  // put your main code here, to run repeatedly:
  for(int i=0; i<3; i++){
    digitalWrite(pinLED[i], HIGH);
    delay(200);
    digitalWrite(pinLED[i], LOW);
    delay(200);
  }
  for(int i=3; i>0; i--){
    digitalWrite(pinLED[i], HIGH);
    delay(200);
    digitalWrite(pinLED[i], LOW);
    delay(200);

  }

}