P21355 [HackerEarth] There are n cities in Wisdom, numbered from 1 to n, connected by m bidirectional roads.
普及
题目描述

There are n cities in Wisdom, numbered from 1 to n, connected by m bidirectional roads.
The j-th road connects city aj and bj.

For tourists, souvenirs are sold in every city of Wisdom. In particular, city i sell it at a price of wi.

Now there are q queries for you to handle. There are two types of queries:

"C a w": The price in city a is changed to w.
"A a b": Now a tourist will travel from city a to b. He will choose a route, he also doesn't want to visit a city twice. He will buy souvenirs at the city where the souvenirs are the cheapest (possibly exactly at city a or b). You should output the minimum possible price that he can buy the souvenirs during his travel.

More formally, we can define routes as follow:

A route is a sequence of cities [x1, x2, ..., xk], where k is a certain positive integer.
For any 1 ≤ i < j ≤ k, xi ≠ xj.
For any 1 ≤ i < k, there is a road connecting xi and xi + 1.
The minimum price of the route is min(wx1, wx2, ..., wxk).
The required answer is the minimum value of the minimum prices of all valid routes from a to b.

Input
The first line of input contains three integers n, m, q (1 ≤ n, m, q ≤ 105), separated by a single space.
Next n lines contain integers wi (1 ≤ wi ≤ 109).
Next m lines contain pairs of space-separated integers aj and bj (1 ≤ aj, bj ≤ n, aj ≠ bj).

It is guaranteed that there is at most one road connecting the same pair of cities. There is always at least one valid route between any two cities.
Next q lines each describe a query. The format is "C a w" or "A a b" (1 ≤ a, b ≤ n, 1 ≤ w ≤ 109).

Output
For each query of type "A", output the corresponding answer.

SAMPLE INPUT
3 3 3
1
2
3
1 2
2 3
1 3
A 2 3
C 1 5
A 2 3

SAMPLE OUTPUT
1
2

输入格式

见题面

输出格式

见题面

样例输入
7 9 4 1 2 3 4 5 6 7 1 2 2 5 1 5 2 3 3 4 2 4 5 6 6 7 5 7 A 2 3 A 6 4 A 6 7 A 3 3
样例输出
2 1 5 3