In an undirected graph, (i,j) means that node i and node j are connected with an undirected edge.
The nodes are numbered from 0 to 11, and the edges are: (3,0) (0,2) (8,11) (9,2) (0,10) (2,4) (5,6) (2,10) (7,1) (0,5) (8,5) (1,0) (9,3) (4,7).