Hi all. I got AC on 3255 using a variant of Dijkstra's algorithm
(expanding twice instead of only once). After getting AC I used this test case:

6 6
1 2 4
2 3 3
3 6 1
6 5 3
5 4 2
4 1 3

And it outputs 8 (which is wrong, since the shortest path has also a total length of 8).

Then, what is the correct approach to this problem ?