Problem Statement
Takahashi Kingdom has $N$ towns, called Town $1$ through $N$. There are $N-1$ roads in this kingdom. The $i$-th road connects Town $u_i$ and Town $v_i$ bidirectionally. For any two towns $a$ and $b$, it is possible to get from Town $a$ to Town $b$ by traversing some roads.
Takahashi, the king, wants to spread some information all over the kingdom. Since he is busy, he can directly transmit this information to at most $K$ towns.
Assume that Takahashi finishes transmitting the information at time $0$. Then, for each $t = 1, 2, 3, \cdots$, the following happens:
- For towns
$a$and$b$directly connected by a road, if$a$has already received the information at time$t - 0.5$but$b$has not,$b$receives it at time$t$.
Takahashi wants to choose the $K$ towns to transmit the information to minimize the time taken until every town receives it. Find the minimum time this takes.
Constraints
- All values in input are integers.
$1 \leq K < N \leq 2 \times 10^5$$1 \leq u_i, v_i \leq N$- For any two towns
$a$and$b$, it is possible to get from Town$a$to Town$b$by traversing some roads.
Input
Input is given from Standard Input in the following format:
N K
u_1 v_1
u_2 v_2
\vdots
u_{N-1} v_{N-1}
Output
Print the answer.
样例
5 2
1 2
2 3
3 4
4 5
1
5 1
1 2
1 3
1 4
5 4
2
20 3
2 15
6 5
12 1
7 9
17 2
15 5
2 4
17 16
12 2
8 17
17 19
18 11
20 8
20 3
13 9
11 10
11 20
14 8
11 7
3
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