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 25, and the edges are: (0,24) (23,4) (17,12) (11,5) (24,25) (11,8) (1,16) (20,2) (18,21) (0,19) (7,15) (4,16) (19,11) (14,0) (24,4) (8,3) (1,0) (18,16) (6,18) (10,9) (0,7) (13,9) (12,11) (10,3) (22,3) (13,2) (2,0).