data/cycle/graph_structure/hard/graph1020.txt

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