In a question asking for the maximum numbers of identical cubes that can be obtained by cutting a larger cube 61 times, the answer was derived by taking the cube to be cut 20 times along 2 of the 3 axes, and 21 times along the third axes(total 61 cuts). But I am not able to understand how can a cube be cut unequal number of times along different axes to get the max number of resultant identical cubes. I can make out 20*20*20 cuts along the 3 different axes, but how does the 21st cut result in final set of identical cubes?