v 0 0 0 v 0 0 1 v 0 1 0 v 0 1 1 v 1 0 0 v 1 0 1 v 1 1 0 v 1 1 1 vt 0 0 #1 vt 0 1 #2 vt 1 0 #3 vt 1 1 #4 f 1/2 3/1 7/3 f 1/2 7/3 8/4 f 5/2 7/1 8/3 f 5/2 8/3 6/4 f 6/2 8/1 4/3 f 6/2 4/3 2/4 f 2/2 4/1 3/3 f 2/2 3/3 1/4 f 3/2 4/1 8/3 f 3/2 8/3 7/4 f 6/2 2/1 1/3 f 6/2 1/3 5/4