Unfortunately, it turns out that a lot of the shows you've been watching this season haven't really lived up to their hype. To vent your frustration, you've decided to spend the weekend jumping in a tree instead.

The tree you're jumping in is rooted at node with nodes connected by edges, the -th edge connecting nodes and with a length of . Each node has values and .

You may jump from node to node if is a descendant of and , with a danger factor of where is the length of the shortest path from to .

For each node from to , find the minimum danger factor of a **direct** jump from some node to node or determine that it is impossible to jump to this node.

#### Constraints

##### Subtask 1 [30%]

and for all .

##### Subtask 2 [70%]

No additional constraints.

#### Input Specification

The first line contains an integer .

The second line contains integers .

The third line contains integers .

The next lines each contain integers , , and .

#### Output Specification

Output lines, the -th line containing the minimum danger factor of a direct jump from some node to node or `Unreachable`

if it is impossible to jump to this node. Your output will be considered correct if the absolute or relative error of each numerical value does not exceed .

#### Sample Input

```
7
11 8 7 2 6 3 9
2 1 1 5 4 3 13
2 4 3
1 2 3
7 1 4
3 6 6
2 3 2
5 3 1
```

#### Sample Output

```
0.300000000000
0.285714285714
1.000000000000
0.333333333333
1.375000000000
Unreachable
```

#### Explanation

For node , it is best to jump from node to node with a danger factor of .

For node , it is best to jump from node to node with a danger factor of .

For node , it is best to jump from node to node with a danger factor of .

For node , it is best to jump from node to node with a danger factor of .

For node , it is best to jump from node to node with a danger factor of .

For node , it is impossible to jump to this node.

## Comments