Assume that we are in a building with \(N\) storeys. There is one elevator in the building. Whenever there is no one waiting to use the elevator, the elevator will always go to the \(x\) storey and remain there until someone wishes to use it. Then, it will go to the storey that the person who wishes to use it is at and fetch that person to the storey that he wishes to go to. Assuming that the people in the building do not visit each other within the building, what value of \(x\) will result in the least energy wasted?