Let f :  R → R and  g : R → R be respectively given by  f (x) = | x |  + 1 and  g (x) = x² + 1. Define h : R → R by

h (x) =  $\{\begin{array}{l}\max \left\{\mathrm{f}\left(\mathrm{x}\right),\mathrm{g}\left(\mathrm{x}\right)\right\}\mathrm{if}\mathrm{x}\le 0\\ \min \left\{\mathrm{f}\left(\mathrm{x}\right),\mathrm{g}\left(\mathrm{x}\right)\right\}\mathrm{if}\mathrm{x}>0\end{array}$.

The number of points at which h (x) is not differentiable is