ElementAtObservable.java

        Observable.just(1, 2, 3, 4, 5, 6)
                .elementAt(1)
                .subscribe(new MaybeObserver<Integer>() {
                    @Override
                    public void onSubscribe(Disposable d) {

                    }

                    @Override
                    public void onSuccess(Integer integer) {
                        System.out.println("onNext: " + integer);
                    }

                    @Override
                    public void onError(Throwable e) {

                    }

                    @Override
                    public void onComplete() {

                    }
                });