for the following graph
- draw the bfs tree, starting from vertex 1
(and show nontree edges as dashed lines)
- draw the dfs tree, starting from vertex 1
(and show back edges as dashed lines)
- list the blocks (biconnected components)
in the order which they would be found
by the algorithm from the notes
(list each block by listing its edges
in the order in which they would be popped
off the stack; circle the back edges)

1: 5 6 12
2: 4 8 9 11
3: 9 11
4: 2 8
5: 1 6
6: 1 5 12
7: 12 13
8: 2 4
9: 2 3 12
10: 12
11: 2 3
12: 1 6 7 9 10
13: 7