In choosing a toilet stall in a public bathroom, people want privacy and refuse to use one adjacent to an occupied stall. So, given a row of n stalls, the first person to arrive will choose an end stall and the second to arrive will choose the opposite end stall. From then on, a anybody arriving makes the greedy choice of the stall furthest away on each side of occupied stalls; if all remaining stalls are adjacent to an occupied stall, the person just leaves. Let U(n) be the maximum number of people that this protocol can service; analyze U(n)