Find the number of spanning trees of a dumbbell graph. A (k, l)-dumbbell graph is obtained by taking a complete graph on k
(labeled) nodes and a complete graph on l (labeled) nodes, and connecting them
by a single edge. Find the number of spanning trees of a dumbbell graph.
Do I have use Kruskal's algorithm for this problem? I am not sure where to begin. 

Hints


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*There is one edge of your graph which must be included in any spanning tree.

*The number of spanning trees in a complete graph is known, see https://oeis.org/A000272
