Answer should be 14.
First take a complete graph with 4 vertices with edge weights (1,2,3,4,5,6) such that (1,2,3) and (4,5,6) forms a cycle. So that we can get maximum MST.
This maximum MST has weight=1+2+4=7.
Now we still need to connect one vertex and we can do this by choosing the minimum of the remaining edges,i.e, edge with weight 7.
So total weight = 7+7=14.