private Player study(Player player) {
		ArrayList<Flashdrive> fInv = new ArrayList<Flashdrive>();
		fInv = player.getFlash();
		ArrayList<Textbook> tInv = new ArrayList<Textbook>();
		tInv = player.getBooks();
		boolean studying = true;
		Scanner in = new Scanner(System.in);
		String response;
		while (studying) {
			System.out.println("What do you want to do? You can... \n"
				+ "Read textbook. \n"
				+ "Use flashdrive. \n"
				+ "Stop studying. ");
			response = in.nextLine();
			if (response.equals("Read textbook.")) {
				System.out.println("What textbook do you want to read? Input the number of the book you want to read.");
				int i = 0;
				for (Textbook book : tInv) {
					i++;
					System.out.println(i + ". " + book.getName());
				}
				int num = in.nextInt() - 1;
				System.out.println(tInv.get(num).getDesc());
				System.out.println("You gain " + tInv.get(num).getKnowledge() + " knowledge.");
				player.addKnowledge(tInv.get(num).getKnowledge());
				player.removeTextbook(num);
				tInv.remove(num);
			}
			else if (response.equals("Use flashdrive.")) {
				int counter = 0;
				int knowledge = 0;
				for (Flashdrive flash : fInv) {
					counter++;
					knowledge = flash.getKnowledge() + knowledge;
				}
				for (int i = fInv.size(); i <= 0; i--) {
					player.removeFlashdrive(i);
				}
				System.out.println("You used " + counter + " flashdrives and gained " + knowledge + " knowledge.");
				player.addKnowledge(knowledge);
			}
			else if (response.equals("Stop studying.")) {
				studying = false;
			}
			else {
				System.out.println("Invalid response.");
			}
		}
		
		
		return player;
	}