A Polish town had just one cow to its name and its milk ran dry. The townsfolk did some research and bought a replacement cow from Minsk for only 1,000 rubles. It was a great cow, gave lots of milk and lots of cream. Everybody loved it.

Then the people decided they would mate the cow and get more cows and would never again have to worry about their milk supply. They bought a bull and led the cow and the bull into the pasture. But things were not that easy - when the bull came in from the right to mount the cow, the cow moved to the left and when the bull moved in to mount the cow from the left, the cow moved to the right. This went on all day.

In desperation, the people asked their rabbi what to do - he was very wise.

"Rabbi, we've tried all day to mate our cow, but when the bull moves in from the right the cow moves left, and vice versa. What shall we do?"

The Rabbi said to them, "Nu, why did you buy a Minsk cow?"

"Rabbi," they said, "you are so wise. We never told you that we bought the cow from Minsk. How did you know?"

The Rabbi said, "My wife is from Minsk."