n28
1,2,3,4,5,6;
0,4,5,7,8,9;
0,7,10,11,12,13;
0,8,10,14,15,16;
0,1,5,11,14,17;
0,1,4,12,15,18;
0,9,13,16,17,18;
1,2,11,12,19,20;
1,3,14,15,19,21;
1,6,17,18,20,21;
2,3,20,21,22,23;
2,4,7,12,22,24;
2,5,7,11,23,25;
2,6,19,21,24,25;
3,4,8,15,22,26;
3,5,8,14,23,27;
3,6,19,20,26,27;
4,6,9,18,24,26;
5,6,9,17,25,27;
7,8,13,16,22,23;
7,9,10,16,24,25;
8,9,10,13,26,27;
10,11,14,19,25,27;
10,12,15,19,24,26;
11,13,17,20,23,27;
12,13,18,20,22,26;
14,16,17,21,23,25;
15,16,18,21,22,24.