Почему валидатор считает что я не записывая два файла в первый?

BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        FileOutputStream outputStream = new FileOutputStream(reader.readLine());
        FileInputStream inputStream1 = new FileInputStream(reader.readLine());
        FileInputStream inputStream2 = new FileInputStream(reader.readLine());

        byte[] buff1 = new byte[inputStream1.available()];
        inputStream1.read(buff1);
        outputStream.write(buff1);
        inputStream1.close();
        byte[] buff2 = new byte[inputStream2.available()];
        inputStream2.read(buff2);
        outputStream.write(buff2);
        reader.close();
        inputStream2.close();
        outputStream.close();