<｜begin▁of▁sentence｜>### Instruction:
As a meeting planner, imagine we're laying out the networking plan for an upcoming conference. We have a diagram illustrating the various connections between discussion groups, which are represented as points 1 through 9, and there's a pathway of communication indicated by lines connecting these points, like a map of how information will flow between the groups.

Now, to ensure the information is well-distributed and efficiently channeled without over-complicating the network, we're interested in figuring out the "treewidth" of our conference's discussion network. This is a bit like determining the ideal number of simultaneous discussions to avoid information overload, while still maintaining comprehensive coverage of all topics.

In our network map, the current connections are as follows: [(1, 2), (1, 3), (2, 3), (2, 4), (3, 4), (3, 5), (3, 6), (4, 5), (4, 6), (5, 6), (7, 8)], with group 9 having no connections at this point, effectively making it an isolated point of discussion. Could you help us determine the treewidth for this network structure, so we can optimize the flow and balance of our conference discussions?
### Response:
import networkx as nx

# Create a chordal graph
G = nx.Graph()
G.add_edges_from([
    (1, 2),
    (1, 3),
    (2, 3),
    (2, 4),
    (3, 4),
    (3, 5),
    (3, 6),
    (4, 5),
    (4, 6),
    (5, 6),
    (7, 8),
])
G.add_node(9)

# Calculate the treewidth of the chordal graph
try:
    treewidth = nx.chordal_graph_treewidth(G)
    print('The treewidth of the graph is:', treewidth)
except nx.NetworkXError as e:
    print(e)
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