#D4077. Forest
Forest
Forest
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
inputFormat
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
outputFormat
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
样例
1 0
5
0