#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using P = pair<int, int>;
using PLL = pair<ll, ll>;
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define repn(i,n) for(int i = 0; i <= (int)(n); i++)
#define srep(i,l,n) for(int i = l; i < (int)(n); i++)
#define srepn(i,l,n) for(int i = l; i <= (int)(n); i++)
#define drep(i,n) for(int i = (int)(n-1); i >= 0; i--)
#define drepn(i,n) for(int i = (int)(n); i >= 0; i--)
#define debug(var)  do{std::cout << #var << " : ";view(var);}while(0)
template<typename T> void view(T e){std::cout << e << std::endl;}
template<typename T> void view(const std::vector<T>& v){for(const auto& e : v){ std::cout << e << " "; } std::cout << std::endl;}
template<typename T> void view(const std::vector<std::vector<T> >& vv){ for(const auto& v : vv){ view(v); } }
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }
template<class T> T gcd(T a, T b) {if(b==0)return a; else return gcd(b,a%b);}
template<class T> T lcm(T a, T b) {return a/gcd(a,b)*b;}
template<class T = int> using V = vector<T>;
template<class T = int> using VV = vector<V<T>>;
bool isIn(int i, int j, int h, int w) {return i >= 0 && i < h && j >= 0 && j < w;}
void Yes(){cout << "Yes" << endl;}
void No(){cout << "No" << endl;}
void YES(){cout << "YES" << endl;}
void NO(){cout << "NO" << endl;}
void err() {cout << -1 << endl;}
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define pb push_back
#define ep emplace_back

const int MOD = 1000000007;
const int INF = 1e9;

#define PI acos(-1);
int dx[4] = {1,-1,0,0};
int dy[4] = {0,0,1,-1};
int ddx[8] = {1,1,1,-1,-1,-1,0,0};
int ddy[8] = {0,1,-1,0,1,-1,1,-1};

class UnionFind{
public:
    vector<ll> par;
    vector<ll> siz;

    UnionFind(ll k):par(k), siz(k, 1LL){
        rep(i,k) par[i] = i;
    }

    ll root(ll x){
        if(par[x]==x) return x;
        else return par[x] = root(par[x]);
    }

    void unite(ll x, ll y){
        x = root(x);
        y = root(y);
        if(x==y) return;

        if(siz[x]<siz[y]) swap(x, y);
        par[y] = x;
        siz[x] += siz[y];
        return;
    }

    bool same(ll x, ll y){
        return root(x) == root(y);
    }

    ll size(ll x){
        return siz[root(x)];
    }
};

const int mxN = 1e5 + 5;
V<> adj[mxN];
bool seen[mxN] = {false};
int gr[mxN] = {0};
int g = 0;

void dfs(int v, int par) {
    for(auto u : adj[v]) {
        if(u == par) continue;
        gr[u] = g;
        seen[u] = true;
        dfs(u, v);
    }
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n, m;
    cin >> n >> m;
    V<> a(n);
    UnionFind uf(n);
    for(int i = 0; i < n; i++) cin >> a[i];
    for(int i = 0; i < m; i++) {
        int a, b;
        cin >> a >> b;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }
    if(2 * (n - m - 1) > n) {
        cout << "Impossible" << endl;
        return 0;
    }
    for(int i = 0; i < n; i++) {
        if(!seen[i]) seen[i] = true, gr[i] = g, dfs(i, -1), g++;
    }
    if(g == 1) {
        cout << 0 << endl;
        return 0;
    }
    V<multiset<ll>> s(g);
    for(int i = 0; i < n; i++) {
        s[gr[i]].insert(a[i]);
    }
    ll ans = 0;
    for(int i = 0; i < g; i++) {
        ans += *s[i].begin();
        s[i].erase(s[i].begin());
    }
    V<ll> p;
    for(int i = 0; i < g; i++) {
        for(auto u : s[i]) p.push_back(u);
    }
    sort(all(p));
    int t = 2 * (n - m - 1) - g;
    for(int i = 0; i < t; i++) {
        ans += p[i];
    }
    cout << ans << endl;
}

Measured memory_bytes: 17668