Suppose there is a list of relations of users in haskell, like this [(user1, user2), (user8,user3)..] and so on, inside a code that's a Social network. The goal is to make a function that is able to tell if there's a group of at least 4 users or more in which the first one is a certain user and the last is another certain user, and each one of the left has to be related with the one at his right. If a sequence like this exists, then it should return true. Maintain it simple