3. (25 points) Visiting all edges. Suppose you have a connected network of two-way streets. Show that you can drive along these streets so that you visit all streets and you drive along each side of every street exactly once. Further, show that you can do this such that, at each intersection, you do not leave by the street you first used to enter that intersection unless you have previously left via all other streets from that intersection. 3. (25 points) Visiting all edges. Suppose you have a connected network of two-way streets. Show that you can drive along these streets so that you visit all streets and you drive along each side of every street exactly once. Further, show that you can do this such that, at each intersection, you do not leave by the street you first used to enter that intersection unless you have previously left via all other streets from that inter