x | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | a | b | c | d | e | f |
S(x) | e | 4 | b | 1 | 7 | 9 | c | a | d | 2 | 0 | f | 8 | 5 | 3 | 6 |