Zebra Puzzle - known logic problem, according to legend founded by Albert Einstein during his childhood. Also, there is a perception that it was used to test Einstein candidates assistants the ability to think logically. Sometimes the author of the puzzle called Lewis Carroll. However, there is no evidence that the problem came up with Einstein or Carroll. (According to Wikipedia)

In the general case, the condition is:
On the street there are several houses, each a different color, they are people of different nationalities, with different habits, pets, and so on. Also provides a list of the facts known about the inhabitants of the houses. You need, based on the logic to determine who lives in what house, what, what pet and so on.

The proposed program lets you try your hand at solving such problems.