Developers are working on a new mapping library to help road planning. They are working on a new approach to minimize distances between places. Currently, there are two networks of places network A and network $B$ in the form of two trees. The number of nodes in each network are networkA$\_$nodes and networkB$\_$nodes respectively. There is an undirected edge from networkA$\_$from$[$i$]$ to networkA$\_$to$[$i$](1i$ networkA$\_$nodes$)$ in networkA. Similarly, there is an undirected edge from networkB$\_$from $[$i$]$ to networkB$\_$to$[$i$]i$ networkB$\_$nodes$)$ in networkB.