题目描述
We have a tree $T$ with vertices numbered $1$ to $N$. The $i$\-th edge of $T$ connects vertex $u_i$ and vertex $v_i$.
Let us use $T$ to define the **similarity** of a permutation $P = (P_1,P_2,\ldots,P_N)$ of $(1,2,\ldots,N)$ as follows.
- For a simple path $x=(x_1,x_2,\ldots,x_k)$ in $T$, let $y=(P_{x_1}, P_{x_2},\ldots,P_{x_k})$. The similarity is the maximum possible length of a longest common subsequence of $x$ and $y$.
Construct a permutation $P$ with the minimum similarity.
What is a subsequence?
A **subsequence** of a sequence is a sequence obtained by removing zero or more elements from that sequence and concatenating the remaining elements without changing the relative order. For instance, $(10,30)$ is a subsequence of $(10,20,30)$, but $(20,10)$ is not.
What is a simple path?
For vertices $X$ and $Y$ in a graph $G$, a **walk** from $X$ to $Y$ is a sequence of vertices $v_1,v_2, \ldots, v_k$ such that $v_1=X$, $v_k=Y$, and there is an edge connecting $v_i$ and $v_{i+1}$. A **simple path** (or simply a **path**) is a walk such that $v_1,v_2, \ldots, v_k$ are all different.
输入格式
The input is given from Standard Input in the following format:
>$N$
$u_1$ $v_1$
$u_2$ $v_2$
$\vdots$
$u_{N-1}$ $v_{N-1}$
#### Constraints
- $2 \leq N \leq 5000$
- $1\leq u_i,v_i\leq N$
- The given graph is a tree.
- All numbers in the input are integers.
输出格式
Print a permutation $P$ with the minimum similarity, separated by spaces. If multiple solutions exist, you may print any of them.
样例输入 #1
3 1 2 2 3
样例输出 #1
3 2 1
样例输入 #2
4 2 1 2 3 2 4
样例输出 #2
3 4 1 2