How to change text on a back button

Question

By default the back button uses as a text on it a title of a viewcontroller. Can I change text on the back button without changing a title of a view controller? I need this

Answer 1

self.navigationController.navigationBar.topItem.backBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"Back" style:UIBarButtonItemStylePlain target:nil action:nil];