#pragma GCC optimize ("O3")
#pragma GCC target ("avx")
#include "bits/stdc++.h" // define macro "/D__MAI"

using namespace std;
typedef long long int ll;

#define debugv(v) {printf("L%d %s > ",__LINE__,#v);for(auto e:v){cout<<e<<" ";}cout<<endl;}
#define debuga(m,w) {printf("L%d %s > ",__LINE__,#m);for(int x=0;x<(w);x++){cout<<(m)[x]<<" ";}cout<<endl;}
#define debugaa(m,h,w) {printf("L%d %s >\n",__LINE__,#m);for(int y=0;y<(h);y++){for(int x=0;x<(w);x++){cout<<(m)[y][x]<<" ";}cout<<endl;}}
#define ALL(v) (v).begin(),(v).end()
#define repeat(cnt,l) for(auto cnt=0ll;(cnt)<(l);++(cnt))
#define rrepeat(cnt,l) for(auto cnt=(l)-1;0<=(cnt);--(cnt))
#define iterate(cnt,b,e) for(auto cnt=(b);(cnt)!=(e);++(cnt))
#define diterate(cnt,b,e) for(auto cnt=(b);(cnt)!=(e);--(cnt))
#define MD 1000000007ll
#define PI 3.1415926535897932384626433832795
template<typename T1, typename T2> ostream& operator <<(ostream &o, const pair<T1, T2> p) { o << "(" << p.first << ":" << p.second << ")"; return o; }
template<typename T> T& maxset(T& to, const T& val) { return to = max(to, val); }
template<typename T> T& minset(T& to, const T& val) { return to = min(to, val); }
void bye(string s, int code = 0) { cout << s << endl; exit(code); }
mt19937_64 randdev(8901016);
inline ll rand_range(ll l, ll h) {
    return uniform_int_distribution<ll>(l, h)(randdev);
}

#if defined(_WIN32) || defined(_WIN64)
#define getchar_unlocked _getchar_nolock
#define putchar_unlocked _putchar_nolock
#elif defined(__GNUC__)
#else
#define getchar_unlocked getchar
#define putchar_unlocked putchar
#endif
namespace {
#define isvisiblechar(c) (0x21<=(c)&&(c)<=0x7E)
    class MaiScanner {
    public:
        template<typename T> void input_integer(T& var) {
            var = 0; T sign = 1;
            int cc = getchar_unlocked();
            for (; cc<'0' || '9'<cc; cc = getchar_unlocked())
                if (cc == '-') sign = -1;
            for (; '0' <= cc && cc <= '9'; cc = getchar_unlocked())
                var = (var << 3) + (var << 1) + cc - '0';
            var = var * sign;
        }
        inline int c() { return getchar_unlocked(); }
        inline MaiScanner& operator>>(int& var) { input_integer<int>(var); return *this; }
        inline MaiScanner& operator>>(long long& var) { input_integer<long long>(var); return *this; }
        inline MaiScanner& operator>>(string& var) {
            int cc = getchar_unlocked();
            for (; !isvisiblechar(cc); cc = getchar_unlocked());
            for (; isvisiblechar(cc); cc = getchar_unlocked())
                var.push_back(cc);
            return *this;
        }
        template<typename IT> void in(IT begin, IT end) { for (auto it = begin; it != end; ++it) *this >> *it; }
    };
    class MaiPrinter {
    public:
        template<typename T>
        void output_integer(T var) {
            if (var == 0) { putchar_unlocked('0'); return; }
            if (var < 0)
                putchar_unlocked('-'),
                var = -var;
            char stack[32]; int stack_p = 0;
            while (var)
                stack[stack_p++] = '0' + (var % 10),
                var /= 10;
            while (stack_p)
                putchar_unlocked(stack[--stack_p]);
        }
        inline MaiPrinter& operator<<(char c) { putchar_unlocked(c); return *this; }
        inline MaiPrinter& operator<<(int var) { output_integer<int>(var); return *this; }
        inline MaiPrinter& operator<<(long long var) { output_integer<long long>(var); return *this; }
        inline MaiPrinter& operator<<(char* str_p) { while (*str_p) putchar_unlocked(*(str_p++)); return *this; }
        inline MaiPrinter& operator<<(const string& str) {
            const char* p = str.c_str();
            const char* l = p + str.size();
            while (p < l) putchar_unlocked(*p++);
            return *this;
        }
        template<typename IT> void join(IT begin, IT end, char sep = '\n') { for (auto it = begin; it != end; ++it) *this << *it << sep; }
    };
}
MaiScanner scanner;
MaiPrinter printer;



class Unionfind {
public:
    vector<int> data;
    Unionfind(size_t size) : data(size, -1) { }
    bool connect(size_t x, size_t y) {
        x = root(x); y = root(y);
        if (x != y) {
            if (data[y] < data[x]) swap(x, y);
            data[x] += data[y]; data[y] = (int)x;
        }
        return x != y;
    }
    inline bool same(size_t x, size_t y) {
        return root(x) == root(y);
    }
    inline size_t root(size_t x) {
        return (size_t)(data[x] < 0 ? x : data[x] = root(data[x]));
    }
    inline int size(size_t x) {
        return -data[root(x)];
    }
};




inline ll top_two(priority_queue<ll>& pq) {
    ll t = pq.top(); pq.pop();
    ll s = t + pq.top();
    pq.push(t);
    return s;
}


ll m, n, kei;

ll aa[100010];

int main() {
    scanner >> n >> m;
    scanner.in(aa, aa + n);

    if (n == 1)
        bye("0");

    Unionfind uf(n);

    repeat(i, m) {
        int x, y;
        scanner >> x >> y;
        uf.connect(x, y);
    }

    stack<pair<ll, int>> pq_1;
    priority_queue<pair<ll, int>> pq;

    vector<priority_queue<ll>> vq(n);
    repeat(i, n) {
        vq[uf.root(i)].push(-aa[i]);
    }
    repeat(i, n) {
        if (uf.root(i) == i) {
            if (vq[i].size() == 1)
                pq_1.emplace(vq[i].top(), i);
            else {
                pq.emplace(top_two(vq[i]), i);
            }
                
        }
    }

    ll ans = 0;

    while (1 < pq.size()) {
        auto p1 = pq.top(); pq.pop();
        auto p2 = pq.top(); pq.pop();

        ans += -vq[p1.second].top() - vq[p2.second].top();
        //cout << make_pair(-p1.first, -p2.first) << endl;
        if (vq[p1.second].size() < vq[p2.second].size())
            swap(p1, p2);
        {
            auto& q1 = vq[p1.second];
            auto& q2 = vq[p2.second];
            q1.pop(); q2.pop();
            // merge q1 << q2
            while (!q2.empty()) {
                q1.push(q2.top());
                q2.pop();
            }

            if (q1.size() == 1)
                pq_1.emplace(q1.top(), p1.second);
            else
                pq.emplace(top_two(q1), p1.second);
        }
    }

    while (!pq_1.empty()) {
        auto p1 = pq_1.top(); pq_1.pop();
        decltype(p1) p2;

        if (pq.empty()) {
            if (pq_1.empty())
                break;
            if (pq_1.size() != 1)
                bye("Impossible");
            p2 = pq_1.top(); pq_1.pop();
            ans += -vq[p1.second].top() - vq[p2.second].top();
            break;
        }
        else
            p2 = pq.top(); pq.pop();

        ans += -vq[p1.second].top() - vq[p2.second].top();
        //cout << make_pair(-p1.first, -p2.first) << endl;

        vq[p2.second].pop();

        if (vq[p2.second].size() == 1)
            pq_1.emplace(vq[p2.second].top(), p2.second);
        else
            pq.emplace(top_two(vq[p2.second]), p2.second);
    }

    cout << ans << endl;

    return 0;
}

Measured memory_bytes: 9344