class Tree():
    def __init__(self,ltree = 0,rtree = 0,data = 0):
        self.ltree = ltree
        self.rtree = rtree
        self.data = data
class BTree():

    def __init__(self,base = 0):
        self.base = base
    def _Empty(self):

        if self.base == 0:
            return True
        else:
            return False
    def qout(self,tree_base):

        if tree_base == 0:
            return
        print tree_base.data
        self.qout(tree_base.ltree)
        self.qout(tree_base.rtree)
    def mout(self,tree_base):

        if tree_base == 0:
            return
        self.mout(tree_base.ltree)
        print tree_base.data
        self.mout(tree_base.rtree)
    def hout(self,tree_base):

        if tree_base == 0:
            return
        self.hout(tree_base.ltree)
        self.hout(tree_base.rtree)
        print tree_base.data