class Node():
    def __init__(self, name, type='dir'):
        self.name = Node
        self.type = type
        self.children = []
        self.parent = None

class FileSystemTree:
    def __init__(self):
        self.root = Node("/")
        self.now = self.root

    def mkdir(self, name):
        if name[-1] != "/":
            name += "/"
        node = Node(name)
        self.now.children.append(node)
        node.parent = self.now