1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
-12: 1 -11: 2 -10: 3 -9: 4 -8: 5 -7: 6 -6: 7 -5: 8 -4: 9 -3: 10 -2: 11 -1: 12 0: 0 1: 1 2: 2 3: 3 4: 4 5: 5 6: 6 7: 7 8: 8 9: 9 10: 10 11: 11 12: 12 0 1 2 3 4 5 6 7 8 9 10 11 12