#include <bits/stdc++.h>
using namespace std;

template <typename A, typename B>
string to_string(pair<A, B> p);

template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p);

template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p);

string to_string(const string& s) {
    return '"' + s + '"';
}

string to_string(const char* s) {
    return to_string((string) s);
}

string to_string(bool b) {
     return (b ? "true" : "false");
}

string to_string(vector<bool> v) {
    bool first = true;
    string res = "{";
    for (int i = 0; i < static_cast<int>(v.size()); i++) {
        if (!first) {
            res += ", ";
        }
        first = false;
        res += to_string(v[i]);
    }
    res += "}";
    return res;
}

template <size_t N>
string to_string(bitset<N> v) {
    string res = "";
    for (size_t i = 0; i < N; i++) {
        res += static_cast<char>('0' + v[i]);
    }
    return res;
}

template <typename A>
string to_string(A v) {
    bool first = true;
    string res = "{";
    for (const auto &x : v) {
        if (!first) {
            res += ", ";
        }
            first = false;
            res += to_string(x);
    }
    res += "}";
    return res;
}

template <typename A, typename B>
string to_string(pair<A, B> p) {
    return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}

template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p) {
    return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " + to_string(get<2>(p)) + ")";
}

template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p) {
    return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " + to_string(get<2>(p)) + ", " + to_string(get<3>(p)) + ")";
}

void debug_out() { cerr << endl; }

template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
    cerr << " " << to_string(H);
    debug_out(T...);
}
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)

#define rep(i,n) for (int i = 0; i < n; ++i)
#define reps(i,s,n) for (int i = s; i < n; ++i)
#define rep1(i,n) for (int i = 1; i <= n; ++i)
#define all(c) begin(c),end(c)
template<typename T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
template<typename T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
void chmax(string &a, string b) {
    if (a == "-") a = b;
    else if (a.size() < b.size()) a = b;
    else if (a.size() == b.size()) {
        if (a < b) a = b;
    }
}
template<typename T> inline T intceil(T a, T b) { return (a + (b - 1)) / b; }
typedef long long ll;
typedef long double ld;
typedef pair<int,int> PINT;
typedef pair<ll,ll> PLL;
const long long MOD = 1e9+7;
#define precout() cout << std::fixed << std::setprecision(20);
#define print(a) cout << a << endl;
const long long INFLL = (1LL << 62) - 1;
const int INFI = (1 << 30) - 1;
template<typename T> void printv(vector<T>&v) {
    int n = v.size() - 1;
    rep(i, n) cout << v[i] << " ";
    cout << v.back() << endl;
}
static const long double pi = acos(-1.0);
const string alphabet = "abcdefghijklmnopqrstuvwxyz";
const int dy[4] = { 0, 1, 0, -1 };
const int dx[4] = { 1, 0, -1, 0 };

using Graph = vector<vector<int>>;
int N, M;
Graph G;
vector<long long> a;

void rec(int v, vector<bool> &seen, vector<int> &comp) {
    seen[v] = true;
    for (auto e : G[v]) {
        if (seen[e]) continue;
        rec(e, seen, comp);
    }
    comp.push_back(v);
}

void solve() {
    vector<vector<int>> comps;
    vector<bool> seen(N, false);
    for (int v = 0; v < N; ++v) {
        if (seen[v]) continue;
        vector<int> comp;
        rec(v, seen, comp);
        comps.push_back(comp);
    }

    int sum = 0;
    for (auto comp : comps) sum += (int)comp.size() - 1;
    if (sum < (int)comps.size()-2) {
        cout << "Impossible" << endl;
        return;
    }
    if (comps.size() == 1) {
        cout << 0 << endl;
        return;
    }

    long long res = 0;
    vector<long long> rem;
    for (auto comp : comps) {
        long long mi = INFLL;
        int pmi = -1;
        for (int i = 0; i < comp.size(); ++i) {
            if (chmin(mi, a[comp[i]])) pmi = i;
        }
        res += mi;
        for (int i = 0; i < comp.size(); ++i) {
            if (i == pmi) continue;
            rem.push_back(a[comp[i]]);
        }
    }
    sort(rem.begin(), rem.end());
    int V = comps.size();
    for (int i = 0; i < V-2; ++i) res += rem[i];
    cout << res << endl;
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);

    cin >> N >> M;
    a.resize(N);
    for (int i = 0; i < N; ++i) cin >> a[i];
    G.assign(N, vector<int>());
    for (int i = 0; i < M; ++i) {
        int x, y; cin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    solve();
}


Measured memory_bytes: 12380