Limits Continuity And Differentiability

Let a function g : [ 0, 4 ] \(\to\) R be defined as

\(g(x) = \left\{ {\matrix{ {\mathop {\max }\limits_{0 \le t \le x} \{ {t^3} - 6{t^2} + 9t - 3),} & {0 \le x \le 3} \cr {4 - x,} & {3 < x \le 4} \cr } } \right.\), then the number of points in the interval (0, 4) where g(x) is NOT differentiable, is ____________.