There are \(n\) stones in a line, and we are going to fetch one away in each operation, so after \(n\) operations the stones are all fetched away. In the first operation, we can fetch any one of the \(n\) stones. But in later operations, only those stones, which have at least one adjacent stone already fetched, can be fetched. For example, assuming there are \(n=5\) stones and we fetch the \(3\)-rd stone in the first operation, then we can only fetch the \(2\)-nd or the \(4\)-th stone in the second operation. Do you know how many different schemes there are to fetch all the stones? Two schemes are different if there exists one operation in which different stones are fetched.