Solid elastic sphere impact with rigid flat surface

i am a student. I would like to simulate impact of an elastic solid ball with rigid flat surface, I do not know how to create the best mesh for the ball so i obtain good results with ansys LS Dyna (drop test modue). of course there are some advice in DTM like avoiding tetrahedron or sharp edges, ... etc. please help me i think a ball meshed with brick element produce better results but, how can one mesh the ball entirely with only  bricks (no tetrahedron)