We are given an undirected graph G = (V, E), |V| ≤ 50. We are also given a starting vertex s. Each vertex v of the graph is associated with a natural number N_v. Initiall our profit is R = N_s.

Now we have to traverse the graph beginning from s in an order. We can visit each vertex or edge an number of times.Whenever we reach a vertex v, R = R XOR N_v. (Note that if we visit a vertex v k times, then we will XOR with N_v k times.

Find the maximum value of R that can be obtained while traversing G.