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Graph TheoryEasyEulerian and Hamiltonian Graphs

Eulerian and Hamiltonian Graphs · Easy problem

A graph has a square A-B-C-D-AA\text{-}B\text{-}C\text{-}D\text{-}A (edges AB,BC,CD,DAAB,BC,CD,DA) with one extra pendant vertex EE attached only to AA (edge AEAE). How many Hamiltonian cycles does this 55-vertex graph have?