How can I make kmeans output cluster label starts with zero and consecutive?

I have used kmeans in mahout.
And I dumped the clusteredPoints directory, but the label starts with CL or
VL , and the label number is not consecutive number.
How can I make the cluster lable consecutive?

p.s I've read the code of ClusterClassificatonDriver, I think for my need
, change the
code of the mapper context write code ,and the problem can be solved. Do
you ever have the same requirement? How do you solve it?