catanedelcu

[url=http://en.wikipedia.org/wiki/Water,_gas,_and_electricity]http://en.wikipedia.org/wiki/Water,_gas,_and_electricity[/url]

e o problema de grafuri arhistudiata.

"The answer to the strict puzzle posed above is no; It is impossible to connect the three cottages with the three different utilities without at least one of the connections crossing another."