p03440 AtCoder Petrozavodsk Contest 001 - 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
```python
# -*- coding: utf-8 -*-
from collections import defaultdict
from heapq import merge
import sys
sys.setrecursionlimit(10**7)
def inpl(): return tuple(map(int, input().split()))
 
N, M = inpl()
A = inpl()
tree = [[-1, 1]  for _ in range(N)] # [next, rank]
 
def find(i):
    if tree[i][0] == -1:
        group = i
    else:
        group = find(tree[i][0]) 
        tree[i][0] = group
    return group
  
def unite(x, y):
    px = find(x)
    py = find(y)
      
    if tree[px][1] == tree[py][1]: # rank is same
        tree[py][0] = px
        tree[px][1] += 1
    else:
        if tree[px][1] < tree[py][1]:
            px, py = py, px
        tree[py][0] = px
  
for _ in range(M):
    x, y = tuple(map(int, input().split()))
    if not int(find(x) == find(y)):
        unite(x, y)
 
D = defaultdict(list)
for n in range(N):
    D[find(n)].append(A[n])
 
H = []
res = 0 

for k, v in D.items():
    v = sorted(v)
    res += v[0]
    H.append(v[1:])
 
if N < 2*(N-M-1):
    print("Impossible")
elif M == N-1:
    print(0)
else:
    res += sum(list(merge(*H))[:2*(N-M-1) - len(D.keys())])
    print(res)
```