// #define _GLIBCXX_DEBUG
#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;
using ll = long long; using pii = pair<int, int>; using vi = vector<int>; using vvi = vector<vi>; using vl = vector<ll>; using vvl = vector<vl>; using vb = vector<bool>; using vvb = vector<vb>;
#define rep0(TMS) for (int CNT = 0; CNT < (int)(TMS); CNT++)
#define rep(CNT, GOAL) for (int CNT = 0; CNT < (int)(GOAL); CNT++)
#define rep2(CNT, START, GOAL) for (int CNT = (int)(START); CNT < (int)(GOAL); CNT++)
#define rep3(CNT, START, GOAL) for (int CNT = (int)(START); CNT > (int)(GOAL); CNT--)
#define all(CONT) begin(CONT), end(CONT)
template <typename T> bool chmax(T &a, const T &b) { if (a < b) { a = b; return true; } return false; }
template <typename T> bool chmin(T &a, const T &b) { if (a > b) { a = b; return true; } return false; }
void prec(const int &DIG) { cout << fixed << setprecision(DIG); cerr << fixed << setprecision(DIG); }
template <typename T> void CERR(const T &ELEM) { cerr << ELEM; }
#define dbl(OBJ) cerr << #OBJ << ": "; CERR(OBJ); cerr << "\n"
template <typename T, typename ...Ts> void CERR(const T &FIRST, const Ts &...REST) { CERR(FIRST); cerr << ", "; CERR(REST...); }
#define dbs(...) cerr << "(" << #__VA_ARGS__ << "): ("; CERR(__VA_ARGS__); cerr << ")\n"
#define itrep(ITR, CONT) for (auto ITR = begin(CONT); ITR != end(CONT); ITR++)
template <typename T> void CERR(const vector<T> &VEC) { cerr << "{ "; itrep(ITR, VEC) { CERR(*ITR); cerr << ", "; } cerr << "}"; }
#define YN(FLG) cout << (FLG ? "YES" : "NO") << "\n"
#define Yn(FLG) cout << (FLG ? "Yes" : "No") << "\n"
#define yn(FLG) cout << (FLG ? "yes" : "no") << "\n"
const ll INF = 1e18; // LONG_LONG_MAX;
// const int INF = INT_MAX;
const ll MOD = 1000000007; // 998244353;

// DSU
namespace atcoder {

// Implement (union by size) + (path compression)
// Reference:
// Zvi Galil and Giuseppe F. Italiano,
// Data structures and algorithms for disjoint set union problems
struct dsu {
  public:
    dsu() : _n(0) {}
    dsu(int n) : _n(n), parent_or_size(n, -1) {}

    int merge(int a, int b) {
        assert(0 <= a && a < _n);
        assert(0 <= b && b < _n);
        int x = leader(a), y = leader(b);
        if (x == y) return x;
        if (-parent_or_size[x] < -parent_or_size[y]) std::swap(x, y);
        parent_or_size[x] += parent_or_size[y];
        parent_or_size[y] = x;
        return x;
    }

    bool same(int a, int b) {
        assert(0 <= a && a < _n);
        assert(0 <= b && b < _n);
        return leader(a) == leader(b);
    }

    int leader(int a) {
        assert(0 <= a && a < _n);
        if (parent_or_size[a] < 0) return a;
        return parent_or_size[a] = leader(parent_or_size[a]);
    }

    int size(int a) {
        assert(0 <= a && a < _n);
        return -parent_or_size[leader(a)];
    }

    std::vector<std::vector<int>> groups() {
        std::vector<int> leader_buf(_n), group_size(_n);
        for (int i = 0; i < _n; i++) {
            leader_buf[i] = leader(i);
            group_size[leader_buf[i]]++;
        }
        std::vector<std::vector<int>> result(_n);
        for (int i = 0; i < _n; i++) {
            result[i].reserve(group_size[i]);
        }
        for (int i = 0; i < _n; i++) {
            result[leader_buf[i]].push_back(i);
        }
        result.erase(
            std::remove_if(result.begin(), result.end(),
                           [&](const std::vector<int>& v) { return v.empty(); }),
            result.end());
        return result;
    }

  private:
    int _n;
    // root node: -1 * component size
    // otherwise: parent
    std::vector<int> parent_or_size;
};

}  // namespace atcoder

using namespace atcoder;

int main() {
	int N, M; cin >> N >> M;
	vi a(N); rep(i, N) cin >> a[i];
	dsu d(N);
	rep0(M) {
		int x, y; cin >> x >> y;
		d.merge(x, y);
	}
	vvi g = d.groups(); int c = g.size(); // c:連結成分の個数=N-M
	if (c == 1) {
		cout << 0 << endl;
		return 0;
	}
	if (N < 2 * (c - 1)) {
		cout << "Impossible" << endl;
		return 0;
	}
	ll ans = 0;
	vi rest;
	for (vi gi : g) {
		vi cost;
		for (int v : gi) cost.push_back(a[v]);
		sort(all(cost));
		ans += cost[0];
		rep2(i, 1, cost.size()) rest.push_back(cost[i]);
	}
	sort(all(rest));
	rep(i, 2 * (c - 1) - c) ans += rest[i];
	cout << ans << endl;
}

Measured memory_bytes: 10380