queries for you to calculate the danger of the least dangerous path from city to city . Because would not like to be robbed, he wants to pay as little as possible at each city to not seem rich. As such, defines the danger of a path as the largest entrance fee that he will have to pay on that path.
has recently been teleported to a strange new world. Here violence is common and the world has been split into tiny city-states. As such, to enter each city will have to pay a certain entrance fee. Moreover, the only safe way to move through this world is through the roads which connect the cities. However, because cities are very careful, each city will be connected to at most 5 other cities. being new to this world, and thinking ahead, hasNote: For each query, and as such will not need to pay the entrance fee of city .
will start at cityConstraints
Each city will be connected to at most 5 other cities.
No city will have a road to itself, and there will only be at max one road between any two cities.
Subtask 1 [15%]
Subtask 2 [30%]
The road network will always be a tree.
Subtask 3 [55%]
No additional constraints.
Input Specification
The first line of input contains , , and representing the number of cities, roads, and queries respectively.
The next line contains integers indicating the entrance cost of each city.
The next lines contain two integers and denoting a road from city to .
The next lines contain two integers and requesting the danger of the least dangerous path from city to city .
Output Specification
For each query , , output the danger of the least dangerous path from city to city , and if there is no valid path, output -1
.
Sample Input
6 7 5
4 3 2 5 1 3
1 2
2 5
3 1
4 2
5 1
5 4
4 3
1 4
5 3
2 3
1 5
1 6
Sample Output
5
4
4
1
-1
Explanation
One of the least dangerous paths from city to city is paying entrance fees of and for cities and respectively, and having a danger of .
One of the least dangerous paths from city to city is paying entrance fees of and for cities and respectively, and having a danger of .
One of the least dangerous paths from city to city is paying entrance fees of and for cities and respectively, and having a danger of .
One of the least dangerous paths from city to city is paying an entrance fee of for city , and having a danger of .
There is no valid path from city to city , thus the output is -1
.
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