Superflip

The superflip or 12-flip is a Rubik's Cube configuration in which all 20 of the movable subcubes (or "cubies") are in the correct permutation, and the eight corners are correctly oriented, but all twelve of the edges are oriented incorrectly ("flipped"). It has been shown that the shortest path between a solved cube and the Superflip position requires 20 moves under the usual half-turn metric (HTM, in which rotating a face 180° counts as a single move), and that no position requires more (although there are many other positions that also require 20 moves).