P6287 [COCI 2016/2017 #1] Mag
Description
You will be given a tree connected by undirected edges. Each node in the tree has a magic value.
We define the magic value of a path as the product of the magic values of all nodes on the path divided by the number of nodes on the path.
For example, if a path contains two nodes with magic values $3,5$, then the magic value of this path is $3\times 5/2=7.5$.
Please compute the magic value of the path with the smallest magic value in this tree.
Input Format
The first line contains an integer $n$, indicating that the tree has $n$ nodes, numbered $1\dots n$.
The next $n-1$ lines each contain two integers $a_i,b_i$, indicating that nodes $a_i$ and $b_i$ are connected by an undirected edge.
The next $n$ lines each contain an integer $x_i$, indicating the magic value of node $i$.
Output Format
Print one line containing a reduced fraction $p/q$.
Explanation/Hint
#### Sample Explanation
**Sample 1 Explanation**
Note that a path may contain only one node.
In this tree, the path with the smallest magic value contains node $1$, and its magic value is $3/1$.
**Sample 2 Explanation**
In this tree, the path with the smallest magic value contains nodes $2,4$, and its magic value is $1\times 1/2=1/2$.
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#### Constraints
For $100\%$ of the testdata, $1\le n\le 10^6$, $1\le a_i,b_i\le n$, $1\le x_i\le 10^9$.
It is guaranteed that $p,q$ will not exceed $10^{18}$.
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#### Notes
**This problem is translated from [COCI2016-2017](https://hsin.hr/coci/archive/2016_2017/) [CONTEST #1](https://hsin.hr/coci/archive/2016_2017/contest1_tasks.pdf) _T4 Mag_.**
Translated by ChatGPT 5