layout = array2d(1..17,1..3, [
48, 27, 46, 
49, 18, 40, 
33, 26, 32, 
36, 14, 6, 
44, 31, 42, 
5, 43, 15, 
38, 10, 29, 
21, 20, 22, 
25, 34, 19, 
52, 13, 37, 
28, 39, 12, 
23, 30, 2, 
47, 7, 3, 
8, 9, 16, 
51, 50, 41, 
24, 45, 35, 
11, 4, 17
]);