 
 import UIKit
 
-class MainPageViewController: UIPageViewController, PFLogInViewControllerDelegate, PFSignUpViewControllerDelegate, UIPageViewControllerDelegate, UIPageViewControllerDataSource {
+class MainPageViewController: UIPageViewController, PFLogInViewControllerDelegate, PFSignUpViewControllerDelegate {
     
     var posts: [Post]!
     var index: Int!

        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
    
    // MARK: - UIPageViewControllerDataSource
    
    func pageViewController(pageViewController: UIPageViewController, viewControllerBeforeViewController viewController: UIViewController) -> UIViewController? {
        print("previous")

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        self.dataSource = self
        
        let vc = UIViewController()
