The earth mover's distance (EMD), also called the first Wasserstein distance, can be naturally extended to compare arbitrarily many probability distributions, rather than only two, on set $[n]=\{1,\dots,n\}$. We present details for this generalization, along with a highly efficient algorithm inspired by combinatorics; it turns out that in special case of three EMD is half sum pairwise EMD's. Ex...