<pre>
Two sets of three knights (one set black, the other white) are placed
at opposite ends of a 3x4 board:

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|-
| N || N || N ||
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|-
|   ||   ||   ||
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|-
|   ||   ||   ||
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|-
| N || N || N ||
 --- --- ---

Using the usual rules for moving a knight in chess, what is the least
number of moves required to exchange the black and white knights?

[[RecPuzzlesKE Solution]]
</pre>
