Chapter 5, Problem 69E

This exercise comes to you courtesy of Euler himself. Here is the question in Euler's own words,

accompanied by the diagram shown in Fig. 5-63.

Let us take an example of two islands with four rivers forming the surrounding water. There are fifteen bridges marked a, b, c, d, etc., across the water around the islands and the adjoining rivers. The question is whether a journey can be arranged that will pass over all the bridges but not over any of them more than once.

Figure 5-63

What is the answer to Euler's question? If the “journey” is possible, describe it. If it isn't, explain why not.