Mock AIME 1 2006-2007 Problems/Problem 2

2. Let $\star (x)$ be the sum of the digits of a positive integer $x$ . $\mathcal{S}$ is the set of positive integers such that for all elements $n$ in $\mathcal{S}$ , we have that $\star (n)=12$ and $0\le n< 10^{7}$ . If $m$ is the number of elements in $\mathcal{S}$ , compute $\star(m)$ .