#include <iostream>
#include <string>
#include <algorithm>
#include <functional>
#include <vector>
#include <stack>
#include <queue>
#include <deque>
#include <set>
#include <map>
#include <cstdio>
#include <cmath>
#include <tuple>
#include <iomanip>
#include <numeric>
#include <unordered_map>
#include <sstream>
#include<limits.h>
#include<float.h>
#include<list>
#include <array>
#include <complex>
#include<stdio.h>
#include<string.h>
#include <bitset>
#include<assert.h>

using namespace std;
#define int long long

#define I32_MAX 2147483647
#define I64_MAX 9223372036854775807LL
#define I64_MAX2 1223372036854775807LL
#define INF I64_MAX2
#define MOD 1000000007
#define MEM_SIZE 10000
#define DEBUG_OUT true
#define ALL(x) (x).begin(), (x).end()

template<typename T> void DEBUG(T e){if(DEBUG_OUT == false)return; std::cout << e <<" ";}
template<typename T> void DEBUG(const std::vector<T>& v){if(DEBUG_OUT == false)return;for(const auto& e : v){std::cout<< e << " "; } std::cout << std::endl;}
template<typename T> void DEBUG(const std::vector<std::vector<T> >& vv){if(DEBUG_OUT == false)return;for(const auto& v : vv){ DEBUG(v); } }
template<class T,class... Ts> void DEBUG(T d, Ts... e){if(DEBUG_OUT == false)return;DEBUG(d);DEBUG(e...);}
template <class T> void corner(bool flg, T hoge) {if (flg) {cout << hoge << endl; abort();}}
template< typename T1, typename T2 > inline bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); }
template< typename T1, typename T2 > inline bool chmin(T1 &a, T2 b) { return a > b && (a = b, true); }


void DFS(int V,vector<vector<int> > &GRAPH,vector<int> &GROUPE,int index)
{
  GROUPE[V] = index;
  for (auto &&nv : GRAPH[V])
  {
    if(GROUPE[nv] == 0)
    {
      DFS(nv,GRAPH,GROUPE,index);
    }
  }
  return;
}

void solve(void)
{
  int N,M;
  cin>>N>>M;
  if(N-1 == M)
  {
    cout<<0<<endl;
    return;
  }
  vector<vector<int> > GRAPH (N);
  vector<int> cost (N,0);
  for (int i = 0; i < N; i++)
  {
     cin>>cost[i];
  }
  for (int i = 0; i < M; i++)
  {
    int A,B;
    cin>>A>>B;
    GRAPH[A].push_back(B);
    GRAPH[B].push_back(A);
  }
  vector<int> GROUPE(N,0);
  int index = 1;
  for (int i = 0; i < N; i++)
  {
    if(GROUPE[i] == 0)
    {
      DFS(i,GRAPH,GROUPE,index);
      index++;
    }
  }
  index--;
  int NI = index;
  // DEBUG(GROUPE);
  int n_add_edge = N - M - 1;
  int n_add_vertex = 2*n_add_edge;
  if(N < n_add_vertex)
  {
    cout<<"Impossible"<<endl;
    return;
  }

  vector<priority_queue<int, vector<int>, greater<int> > > vq(NI);
  for (int i = 0; i < N; i++)
  {
    int I = GROUPE[i];
    I--;
    vq[I].push(cost[i]);
  }
  int res = 0;
  int cnt = 0;
  for (int i = 0; i < NI; i++)
  {
      res += vq[i].top();
      vq[i].pop();
      cnt++;
  }

  priority_queue<int, vector<int>, greater<int> > queue;
  for (int i = 0; i < NI; i++)
  {
    while(!vq[i].empty())
    {
      queue.push(vq[i].top());
      vq[i].pop();
    }
  }
  for (int i = cnt; i < n_add_vertex; i++)
  {
    res += queue.top();
    queue.pop();
  }
  

  
  cout<<res<<endl;
  
  
  

  return;
}
int32_t main(int32_t argc, const char *argv[])
{
  std::ios::sync_with_stdio(false);
  std::cin.tie(0);

  std::cout << std::fixed;
  std::cout << std::setprecision(11);
  solve();

  return 0;
}


Measured memory_bytes: 10496