Algorithm title: 10308

Problem I

Roads in the north

Input:standard input

Output:standard output

Time Limit:2 seconds

Memory limit:32 MB

Building and maintaining roads among communities in the far was an expensive. With this in mind, the roads are built at such a way that there be only one route from a village to a village that does no T pass through some the other village twice.

Given is an area in the far north comprising a number of villages and roads among them-so any such can be village D by road from the other village. The Your job is to find the road distance between the two most remote villages into the area.

The area has up to 10,000 villages connected by road segments. The villages are numbered from 1.

Input

The input contains several sets of input. Each set of input is a sequence of lines, containing three positive integers:the number of a village, the number of A different village, and the length of the road segment connecting the villages in kilometers. All road segments are two-way. Two consecutive sets are separated by a blank line.

Output
For each set of input, you are to output a single line containing a single integer:the road distance between the two most Remote villages in the area.
Sample Input

5 1 6

1 4 5

6 3 9

2 6 8

6 1 7

Sample Output

22