if the rods are too ways
why the sample give an example saying that
it is different between (1,3) and (3,1)

> if the rods are too ways
> why the sample give an example saying that
> it is different between (1,3) and (3,1)

The author has tried to make the problem harder...if there are more
than one way between two towns, you have just to take the shorter
one... Althoug, the testing program of this problem is wrong, for
example if you always write "No solution\n" when no cicle found
and "350000\n" otherwise, you'll get accepted. :)

I don't understand.

If the length of the roads is less than 500 and the answer may contain at most 100 towns, how can the answer be 350000?

100*500=50000 < 350000

Of course, it's impossible. Answer <= 50000.