M(*) |
| (+)n = f(m) |
1 | (1,0) | 0 |
2 | (2,0) | 4 |
3 | (0,1) | 1 |
4 | (1,1) | 2 |
5 | (2,1) | 7 |
7 | (1,2) | 3 |
8 | (2,2) | 6 |