me?

The whole thing is:

...

...Some formula...

Where K denotes the total number of clusters and m is the sum of all members in cluster i.

...

From the context, I figure out that K and m both mean the size. K means how many clusters and m is the size of a cluster. m is not the sum of all the members of cluster i. The member in cluster i is document.

Any suggestions on what to say about this more clearly?

Do inform me if you see any corrections needed in my written English.