Pocket Cube Rubik's cube, simply by treating it as a 3x3x3 with solved (invisible) centers and edges. More advanced methods combine multiple steps and require more algorithms. These algorithms designed for solving a 2x2x2 cube are often significantly shorter and faster than the algorithms one would use for solving a 3x3x3 cube. The Ortega method, also called the Varasano method, is an intermediate method. First a face is built (but the pieces may be permuted incorrectly), then the last layer is oriented (OLL) and lastly both layers are permuted (PBL). The Ortega method requires a total of 12 algorithms. The CLL method
Folded cube graph as many vertices, by identifying together (or contracting) every opposite pair of vertices. An order-"k" folded cube graph is "k"-regular with 2 vertices and 2"k" edges. The chromatic number of the order-"k" folded cube graph is two when "k" is even (that is, in this case, the graph is bipartite) and four when "k" is odd. The odd girth of a folded cube of odd order is "k", so for odd "k" greater than three the folded cube graphs provide a class of triangle-free graphs with chromatic number four and arbitrarily large odd girth. As a distance-regular graph with odd