Continuity and Differentiability

Consider the function f : (- 2, 2 ) (- , ) defined by f(x) = (|x| + |x - 1|) x + [x x] , where [x x] is the greatest integer less than or equal to x x . Let be the total number of points in the interval (- 2, 2 ) at which f is NOT continuous, and let be the total number of points in the interval (- 2, 2 ) at which f is NOT differentiable. Then the value of + is .