# Smart counting

$\begin{eqnarray}\large A&=&\{1,2,3,4,5\} \\ \large B&=&\{6,7,8,9,10\} \end{eqnarray}$

Let $$f:A\to B$$ be a function defined on the sets above.

Find the number of non-decreasing functions $$f$$.

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