# number of nodes
7

# number of different node classes 
4

# node_class node_label (classes IDs go from 1..n)
3 node 1 # spaces allowed in node labels
1 node 2
3 node 3
2 node 4
2 node 5
2 node 6
1 node 7

# number of edges
7

# edges (node IDs go from 1..n)
1 7
5 7
2 3
4 6
4 5
2 6
2 7