Here is a map of the recently discovered cities and canals of our nearest neighboring planet, Mars.
Start in the city marked with an N, at the south pole, and see if you can spell a complete sentence by touring all the cities, visiting them only once and returning to the starting point.
When this riddle appeared in a magazine for the first time, more than fifty thousand readers said: "There is no possible solution." However, it is a very simple puzzle.
The fifty thousand readers who answered "There is no possible solution" They solved the riddle, because that is the phrase that goes around the planet!