bruce 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 bruce 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. bruce being new to this world, and thinking ahead, has
queries for you to calculate the danger of the least dangerous path from city
to city
. Because bruce would not like to be robbed, he wants to pay as little as possible at each city to not seem rich. As such, bruce defines the danger of a path as the largest entrance fee that he will have to pay on that path.
Note: For each query, bruce will start at city
and as such will not need to pay the entrance fee of city
.
Constraints





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
Copy
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
Copy
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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