# This puzzle is unsolvable
7
 2  1  3  4  5  6  7
24 25 26 27 28 29  8
23 41 42 43 30 31  9
22 40 39 48 44 32 10
21 38 47 46 45 33 11
20 37 36 35 34  0 12
19 18 17 16 15 14 13