There are five cities A, B, C, D, E on a certain island. Each city is connected to every other city by road. In how many ways can a person starting from city A come back to A after visiting some cities without visiting a city more than once and without taking same road more than once? (The order in which he visits the cities also matters: e.g. the routes `A->B->C->A` and `A->C->B->A` are different

Answer

60