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 lazy var orderedViewControllers: [UIViewController] = {
        return [self.newViewController(viewController: "firstSB"),
                self.newViewController(viewController: "secondSB"),
                self.newViewController(viewController: "thirdSB"),
                self.newViewController(viewController: "lastSB")]
    }()
    
    var PageControl = UIPageControl()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        self.dataSource = self
        if let FirstViewController = orderedViewControllers.first {
            setViewControllers([FirstViewController],
                               direction: .forward,
                               animated: true,
                               completion: nil)
        }
        
        self.delegate = self
        ConfigurePageControl()
    }
    

    
    //Создаем функцию, которая отображает навигацию снизу
    func ConfigurePageControl() {
        PageControl = UIPageControl(frame: CGRect(x: 0, y: UIScreen.main.bounds.maxY - 50, width: UIScreen.main.bounds.width, height: 50))
        PageControl.numberOfPages = orderedViewControllers.count
        PageControl.currentPage = 0
        PageControl.tintColor = UIColor.white
        PageControl.pageIndicatorTintColor = UIColor.black
        PageControl.currentPageIndicatorTintColor = UIColor.white
        self.view.addSubview(PageControl)
    }

    
    func newViewController(viewController: String) -> UIViewController {
        return UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: viewController)
    }
    
    
    //Обрабатываем свайпы назад
    func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController? {
        guard let ViewControllerIndex = orderedViewControllers.index(of: viewController)
            else {
                return nil
        }
        
        let PreviousIndex = ViewControllerIndex - 1
        
        guard PreviousIndex >= 0 else {
            return nil
        }
        
        guard orderedViewControllers.count > PreviousIndex else {
            return nil
        }
        
        return orderedViewControllers[PreviousIndex]
    }
    
    //Обрабатываем свайпы вперед
    func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController) -> UIViewController? {
       
        guard let ViewControllerIndex = orderedViewControllers.index(of: viewController)
            else {
                return nil
        }
        
        let NextIndex = ViewControllerIndex + 1
        
        guard orderedViewControllers.count != NextIndex else {
            return nil
        }
        
        guard orderedViewControllers.count > NextIndex else {
            return nil
        }
        
        return orderedViewControllers[NextIndex]
    }
    
    
    func pageViewController(_ pageViewController: UIPageViewController, didFinishAnimating finished: Bool, previousViewControllers: [UIViewController], transitionCompleted completed: Bool) {
        let PageContentViewController = pageViewController.viewControllers![0]
        self.PageControl.currentPage = orderedViewControllers.index(of: PageContentViewController)!
    }