Seven Smurfs lived in seven mushroom houses. Papa Smurf, being very organized, built a tunnel between every pair of houses, so that all seven houses were connected to each other. One of the Smurfs, Clumsy, started walking from his house, but followed the rule that he could not walk through a tunnel he had already walked through. He will stop walking whenever he reaches a house with no more tunnels left for him to use. Where will Clumsy’s journey end?