#-*- coding: utf-8-*-

class BinTreeKeyError(Exception):
    pass

class BinTree:
    def __init__(self, key, ls, rs):
        if (type(key) != str) and (type(key) != unicode):
            raise BinTreeKeyError(u'BinTree Key must be a character')
        if len(key) != 1:
            raise BinTreeKeyError(u'BinTree Key must be a character')
        self.key, self.ls, self.rs = key, ls, rs
    
    def __repr__(self):
        return '<%s,%s,%s>' % (hex(ord(self.key)), self.ls, self.rs)