// Slower C++ solution:
#include <algorithm>

#include <iostream>

#include <cstdlib>

#include <cstdio>

#include <string>

#include <vector>

using namespace std;

const int MAXN = 100000;



int n, m;

int fa[MAXN+5];

int val[MAXN+5];

vector <int> blk[MAXN+5];

vector <int> ansEdge;

long long int ans;



int SetFind(int x)

{

    if(fa[x] != x)

        return fa[x] = SetFind(fa[x]);

    return fa[x];

}



void SetInit(int n)

{

    for(int i = 1; i <= n; i++)

        fa[i] = i;

}



int main()

{

    int blkcnt;



    cin >> n >> m ;

    SetInit(n);

    blkcnt = n;



    for(int i = 1; i <= n; i++)

    {

        cin >> val[i] ;

        //blk[i].push_back(val[i]);

    }





    for(int i = 1; i <= m; i++)

    {

        int u, v;

        cin >> u >> v;

        u++, v++;

        if(SetFind(u) != SetFind(v))

            fa[SetFind(u)] = SetFind(v), blkcnt--;

    }



    for(int i = 1; i <= n; i++)

        blk[SetFind(i)].push_back(val[i]);

/*

    for(int i = 1; i <= n; i++)

    {

        if(!blk[i].empty())

            cout << blk[i].size() << endl ;

    }

*/

    if(blkcnt <= 1)

    {

        cout << 0 << endl ;

        return 0;

    }



    blkcnt -= 2;



    for(int i = 1; i <= n; i++)

        if(!blk[i].empty())

        {

            sort(blk[i].begin(), blk[i].end());

            ans += blk[i][0];

            for(int k = 1; k < blk[i].size(); k++)

                ansEdge.push_back(blk[i][k]);

        }



    if(ansEdge.size() < blkcnt)

    {

        cout << "Impossible" << endl;

        return 0;

    }



    sort(ansEdge.begin(), ansEdge.end());



    for(int i = 0; i < blkcnt; i++)

        ans += ansEdge[i] ;



    cout << ans << endl ;

    return 0;

}


// Faster C++ solution for the same problem (measured speedup: 3.5463787203268224x):
#include <bits/stdc++.h>

using namespace std;



#define ll long long

#define sd(x) scanf("%d", &(x))

#define pii pair<int, int>

#define F first

#define S second

#define all(c) ((c).begin()), ((c).end())

#define sz(x) ((int)(x).size())

#define ld long double



template<class T,class U>

ostream& operator<<(ostream& os,const pair<T,U>& p){

	os<<"("<<p.first<<", "<<p.second<<")";

	return os;

}



template<class T>

ostream& operator <<(ostream& os,const vector<T>& v){

	os<<"{";

	for(int i = 0;i < (int)v.size(); i++){

		if(i)os<<", ";

		os<<v[i];

	}

	os<<"}";

	return os;

}



#ifdef LOCAL

#define cerr cout

#else

#endif



#define TRACE



#ifdef TRACE

#define trace(...) __f(#__VA_ARGS__, __VA_ARGS__)

template <typename Arg1>

void __f(const char* name, Arg1&& arg1){

	cerr << name << " : " << arg1 << std::endl;

}

template <typename Arg1, typename... Args>

void __f(const char* names, Arg1&& arg1, Args&&... args){

	const char* comma = strchr(names + 1, ',');cerr.write(names, comma - names) << " : " << arg1<<" | ";__f(comma+1, args...);

}

#else

#define trace(...)

#endif



struct dsu{

    int n;

    vector<int> par;

    vector<vector<int>> comp;

    int num;

    dsu(int n) : n(n), par(n), comp(n), num(n){

        iota(par.begin(), par.end(), 0);

    }

    int root(int x){

        return x == par[x] ? x : (par[x] = root(par[x]));

    }

    bool merge(int x, int y){

        x = root(x); y = root(y);

        if(x == y) return 0;

        par[x] = y;

        num--;

        return 1;

    }

    void get(){

        for(int i = 0; i < n; i++) comp[root(i)].push_back(i);

    }

};





int a[100005];

int main(){

    int n, m; sd(n); sd(m);

    for(int i = 0; i < n; i++) sd(a[i]);

    dsu D(n);

    for(int i = 0; i < m; i++){

        int u, v;

        sd(u); sd(v);

        D.merge(u, v);

    }

    if(D.num == 1){

        printf("0\n");

        return 0;

    }

    D.get();

    vector<int> rem;

    ll ans = 0;

    int num = 0;

    for(int i = 0; i < n; i++) if(!D.comp[i].empty()){

        vector<int> V = D.comp[i];

        sort(all(V), [&](int i, int j){

            return a[i] < a[j];

        });

        ans += a[V[0]];

        for(int j = 1; j < sz(V); j++) rem.push_back(a[V[j]]);

    }

    if(sz(rem) < D.num - 2){

        printf("Impossible\n");

        return 0;

    }

    sort(all(rem));

    for(int i = 0; i < D.num - 2; i++) ans += rem[i];

    printf("%lld\n", ans);

}