Trouble with toilets Bashny.Net

In ancient times, it was organized by the railway company. One
of its leaders (probably commercial director) found that
You can save a lot of money if you do not supply the toilet every
railroad car, but only half of them. So it was decided to
do. However, soon after the start of passenger traffic trouble started
with toilets. The reason they were extremely simple: although the company has just
that created enough confusion already, and disposal of commercial
Director did not know at the sorting stations, where all the cars
We felt the same. As a result, some trains toilets almost
It did not exist.
To remedy the situation, each car added a sign telling,
Does it have a toilet, and the coupler was told to be a train so,
to about half of the cars had toilets. Although this complicated the work
coupler, soon they proudly reported that carefully performed
new instruction.
However, the trouble with the toilet continued. New Farming investigation
their causes showed that while half of the cars actually on the train
equipped with toilets, sometimes it turns out that they are all in one
half train. To save the situation, the instructions were issued,
prescribing alternate cars with toilets and without them. This added
Work coupler, however, grumbled, and they deal with it. But the problem
this is not over. Because the toilets are located at one end of
the car, the distance between two adjacent toilets on the train could
lengths of up to three cars and passengers with children - especially if
Corridors were made luggage - it was too far. Then cars
toilets were equipped with an arrow, and the new guidelines were issued,
prescribes that all the arrows are pointing in the same direction. You can not
said that these regulations have been met in marshalling yards with
enthusiasm - the number of turntables was insufficient, but,
strained, and coupler have learned to do it. Now that all the toilets
are equidistant, the company was confident of success, but
Passengers continued to worry: although the nearest toilet was not
more than one car, but it was not clear which side it is.
To solve this problem, in wagons were drawn arrows
labeled "Toilet" to make the necessary and properly orient
cars without toilets.
At the sorting stations new instruction caused a shock: do
required at the time was impossible. At the critical moment, someone whose name
Now it is impossible to establish the following notice. If we grappled with the car
WC and without it, so that the toilet was in the middle, and never let them
We will disengage, the yard will have a deed in lieu of N
oriented objects with N / 2 objects that can all
relations and from all points of view be considered balanced. This observation
It solved the problem of the cost of the two concessions. First, the train could now
only consist of an even number of cars - cars could be missing
paid for by the savings from reducing the number of toilets, and, secondly,
toilets were situated on slightly unequal distances.
But who are concerned about the extra meter?
Although at the time, which include our history, mankind has never known
Computers, an unknown who has found this solution, was the first in the world competent
programmer.