Recall that a strongly connected graph is one in which there is a path (not necessarily direct) from any vertex to any other vertex. An Euler tour of a strongly connected, directed graph G = (V, E) is a cycle that traverses each edge of G exactly once, although it may visit a vertex more than once. It turns out that G has an Euler tour if and only if in-degree(v) = out-degree(v) for each vertex v V . Give two examples of 4-vertex strongly connected, directed graphs: one that has an Euler tour and one that doesnt.