private void printIsUserExist() throws IOException {
		String s;
		printMenu(PrintMenuName.IS_USER_EXIST);
		while (true) {
			s = br.readLine();
			System.out.println(s);
			if (s.equals("b")) {
				break;
			} else if (s != null && !s.trim().equals("")) {
				System.out.print("User " + s);
				System.out.println(userService.isUserExist(s) ? " is exist" : " does not exist");
			}
		}
		printMenu(PrintMenuName.MAIN_MENU);
	}