class Dictionary(object):
    def __init__(self):
        
        self.__keys=[]
        self.__values=[] 

    def items(self):
        return zip(self.__keys, self.__values)

    def keys(self):
        return self.__keys

    def values(self):
        return self.__values

     

    def __setitem__(self,key,val):
        try:
            index=self.__keys.index(key)
            self.__keys.remove(key)
            self.__values.remove(self.__values[index])
        except: pass
	
	self.__keys.append(key)
	self.__values.append(val)
	
    def __getitem__(self,key):
        index=self.__keys.index(key)
        return self.__values[index]        


    def remove(self, key):
        index=self.__keys.index(key)
        self.__keys.remove(key)
        self.__values.remove(self.__values[index])

d=Dictionary()

d['d']=5
d['d']=23
d[7]='j'
d[7]='wfdwefwefwefw'

print d.keys()
print d.values()
print d.items()    
print d[7]

d.remove(7)

print d.keys()
print d.values()
print d.items()