How to reorder nodes according to their degree through Hadoop MapReduce? [on hold]

I am doing a Project in Hadoop MapReduce and I want to do a preprocessing step of arranging the nodes according to their degree.

The input edge list will be like,

A B

which denotes that a unidirectional edge lies between A and B.

Now, If the node B is having lower degree than A. I want to rearrange it as,

B A.

I am working on a graph with millions of nodes, and this preprocessing step is much important.

Help would be much Appreciated.