#ifndef DEBUG
#  define NDEBUG
#endif
#include <iostream>
#include <algorithm>
#include <string>
#include <iterator>
#include <utility>
#include <type_traits>
#include <limits>
#include <cassert>
#include <numeric>
#include <vector>
#include <array>
#include <map>

using namespace std;

// template {{{
// misc {{{
using Z = long long;
[[maybe_unused]]
constexpr Z INF = numeric_limits<Z>::max() / 3;
// }}}

// debug {{{
template <class T>
using enable_if_sequence_t = enable_if_t<
  is_same<
    typename iterator_traits<
      typename remove_cv_t<remove_reference_t<T>>::iterator
    >::iterator_category,
    random_access_iterator_tag>{}>;
#ifdef NDEBUG
# define dump(x)
# define debug if (0)
template <class T>
inline T&& ix(T&& value) { return value; }
template <class T, class Index, class... Indices, class = enable_if_sequence_t<T>>
inline auto&& ix(T&& container, Index index, Indices... indices) {
  return ix(container[index], indices...);
}
#else
# define dump(x) do { \
    cerr << "\e[33m[dump: " << __LINE__ << "] " << (#x) << " = " << x << "\e[0m" << endl; \
  } while (0);
# define debug
template <class T>
inline auto&& ix_impl([[maybe_unused]] int line, [[maybe_unused]] const char* code, T&& value) {
  return value;
}
template <class T, class Index, class... Indices, class = enable_if_sequence_t<T>>
inline auto&& ix_impl(int line, const char* code, T&& container, Index index, Indices... indices) {
  if (index < 0) {
    cerr << "\e[31mix: negative index at line " << line << ", ix(" << code << ")\n"
      << "index = " << index << "\e[0m" << endl;
    exit(1);
  }
  int size = distance(begin(container), end(container));
  if (index >= size) {
    cerr << "\e[31mix: index out of range at line " << line << ", ix(" << code << ")\n"
      << "index = " << index << " whereas size = " << size << "\e[0m" << endl;
    exit(1);
  }
  return ix_impl(line, code, container[index], indices...);
}
#define ix(...) ix_impl(__LINE__, #__VA_ARGS__, __VA_ARGS__)
#endif
// }}}

// IO {{{
template <class T, class U>
ostream& operator<< (ostream& os, pair<T, U> p) {
  os << '(' << p.first << ", " << p.second << ')';
  return os;
}
template <class T, class U>
istream& operator>> (istream& is, pair<T, U>& p) {
  is >> p.first >> p.second;
  return is;
}
template <class T>
false_type is_container_impl(...);
template <class T, class = typename T::iterator>
true_type is_container_impl(T);
template <class T>
struct is_container : decltype(is_container_impl<T>(declval<T>())) {};
template <>
struct is_container <string> : std::false_type {};
template <class Container, class = enable_if_t<is_container<Container>{}>>
istream& operator>> (istream& is, Container& cont) {
  for (auto& v : cont) is >> v;
  return is;
}
template <class Container, class = enable_if_t<is_container<Container>{}>>
ostream& operator<< (ostream& os, Container const& cont) {
  bool first = true;
  constexpr char sep =
    is_container<typename Container::value_type>{} ? '\n' : ' ';
  for (auto const& v : cont) {
    if (!first) {
      os << sep;
    }
    first = false;
    os << v;
  }
  return os;
}
template <class T>
void conclude(T const& message) {
  cout << message << endl;
  exit(0);
}
// }}}
// }}}


// union_find {{{
class union_find {
  private:
    vector<Z> parent, rank, size;
  public:
    union_find(Z n): parent(n), rank(n, 1), size(n, 1) {
      for (auto i = 0; i < n; i++)
        parent[i] = i;
    }

    Z root(Z x) {
      Z& par = ix(parent, x);
      if (par == x) return x;
      return par = root(par);
    }

    void unite(Z x, Z y) {
      x = root(x);
      y = root(y);
      if (x == y) return;
      if (ix(rank, x) > ix(rank, y))
        swap(x, y);
      ix(parent, x) = y;
      ix(size, y) += ix(size, x);
      if (ix(rank, x) == ix(rank, y))
        ix(rank, y)++;
    }

    bool is_same(Z x, Z y) {
      return root(x) == root(y);
    }

    Z group_size(Z x) {
      return ix(size, root(x));
    }
};
// }}}

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);
  cout.precision(10);
  cout << fixed;
  Z N, M;
  cin >> N >> M;
  vector<Z> as(N);
  cin >> as;
  union_find uf(N);
  for (auto i = 0; i < M; i++) {
    Z x, y;
    cin >> x >> y;
    uf.unite(x, y);
  }
  map<Z, vector<Z>> forest;
  for (auto i = 0; i < N; i++) {
    forest[uf.root(i)].push_back(ix(as, i));
  }
  if (forest.size() == 1) {
    conclude(0);
  }
  Z ans = 0;
  vector<Z> rest;
  for (auto&& t : forest) {
    sort(begin(t.second), end(t.second));
    ans += t.second.front();
    copy(begin(t.second) + 1, end(t.second), back_inserter(rest));
  }
  sort(begin(rest), end(rest));
  Z other = forest.size() - 2;
  if (rest.size() < other) {
    conclude("Impossible");
  }
  ans += accumulate(begin(rest), begin(rest) + other, 0ll);
  cout << ans << '\n';
}



Measured memory_bytes: 14336