12
7 9 12 8 10 11
10 12 7 8 11 9
7 10 11 9 12 8
12 11 9 10 8 7
8 9 7 10 11 12
9 7 8 12 11 10
1 5 6 3 2 4
2 4 6 1 3 5
4 3 6 2 5 1
1 3 5 4 2 6
3 2 6 1 4 5
5 1 3 6 4 2
//
// same problem as in CP2001
// mapped from stable marriage to SRI
//