题目描述
You are given a forest with N vertices and M edges. The vertices are numbered 0 through N-1. The edges are given in the format (x_i,y_i), which means that Vertex x_i and y_i are connected by an edge.
Each vertex i has a value a_i. You want to add edges in the given forest so that the forest becomes connected. To add an edge, you choose two different vertices i and j, then span an edge between i and j. This operation costs a_i + a_j dollars, and afterward neither Vertex i nor j can be selected again.
Find the minimum total cost required to make the forest connected, or print Impossible if it is impossible.
Constraints
- 1 ≤ N ≤ 100,000
- 0 ≤ M ≤ N-1
- 1 ≤ a_i ≤ 10^9
- 0 ≤ x_i,y_i ≤ N-1
- The given graph is a forest.
- All input values are integers.
Input
Input is given from Standard Input in the following format:
N M
a_0 a_1 .. a_{N-1}
x_1 y_1
x_2 y_2
:
x_M y_M
Output
Print the minimum total cost required to make the forest connected, or print Impossible if it is impossible.
Examples
Input
7 5
1 2 3 4 5 6 7
3 0
4 0
1 2
1 3
5 6
Output
7
Input
5 0
3 1 4 1 5
Output
Impossible
Input
1 0
5
Output
0
输入格式
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输出格式
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