PivotOJ

Parkovi

시간 제한: 3000ms메모리 제한: 512MB출처: COCI 2021-2022BOJ 24472

문제

The town administration has decided to embellish the landscape by building new parks. To make the parks not only look good, but also be useful, they need to carefully choose which neighbourhoods to build the parks in so that the kids from the other neighbourhoods have at least one park near them.

The town consists of nn neighbourhoods connected by n1n - 1 roads of a certain length. There is a unique path connecting each neighbourhood to any other neighbourhood. In other words, the neighbourhoods and roads form a tree. Exactly kk parks should be built in different neighbourhoods so that the other neighbourhoods have their nearest park as close to them as possible. To be more precise, the administration wants to minimize the maximum distance from a neighbourhood to its closest park.

Help the town administration and determine which neighbourhoods should have a park built in them and determine the maximum distance from a neighbourhood to its closest park.

입력

The first line contains two positive integers nn and kk (1 ≤ k ≤ n ≤ 200\,000), the number of neighbourhoods and the number of parks, respectively.

The ii-th of the next n1n - 1 lines contains positive integers aia_i, bib_i and wiw_i (1 ≤ a_i , b_i ≤ n, 1 ≤ w_i ≤ 10^9), which denotes that the neighbourhoods labeled aia_i and bib_i are connected by a road of length wiw_i.

출력

In the first line print the least possible maximum distance from the problem statement.

In the second line print kk positive integers, the labels of the neighbourhoods which will have a park built in them. If there is more than one solution, output any one.

힌트

Clarification of the third example: If the parks were built only in neighbourhoods 3 and 4, the maximum distance wouldn’t change, but the city administration wants to build exactly kk parks, so two more need to be built somewhere else.

예제

예제 1

입력
9 3
1 2 5
1 3 1
3 4 10
3 5 9
5 6 8
2 7 1
2 8 2
8 9 7
출력
8
4 5 8

예제 2

입력
5 2
1 2 3
2 3 7
3 4 3
4 5 3
출력
3
2 4

예제 3

입력
7 4
1 3 1
1 4 1
2 3 1
5 3 1
4 7 1
4 6 1
출력
1
3 4 1 2
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