Use the figures below to evaluate the indicated derivative, or state that it does not exist. If the derivative does not exist, enter dne in the answer blank. The graph to the left (in black) gives $f(x)$, while the graph to the right gives $g(x)$ (which is constant for values of $x$ greater than 20).

$f(x)$	$g(x)$

$\frac{d}{dx}f(g(x))|_{x=15} =$
(If the derivative does not exist, enter dne.)