I used reduction from Ham-path:

G,s,t—>G', |V| of g

G' would be same as G except of an edge from s to t, and a simple path from s length |V|.

]]>What reduction did you use in the question with the k-key?

]]>I believe that it should be 2A-1, 2B-c

Am I correct?

Thanks a lot!

]]>