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

#define times(n, i)      uptil(0, n, i)
#define rtimes(n, i)     downto((n) - 1, 0, i)
#define upto(f, t, i)    for(auto i##0_to = (t), i = decltype(t)(f); i <= i##0_to; i++)
#define uptil(f, t, i)   for(auto i##0_to = (t), i = decltype(t)(f); i <  i##0_to; i++)
#define downto(f, t, i)  for(auto i##0_to = decltype(f)(t), i = (f); i >= i##0_to; i--)
#define downtil(f, t, i) for(auto i##0_to = decltype(f)(t), i = (f); i >  i##0_to; i--)
/** types **/
	using LD = long double;
	#define double LD
	#define long long long
	#define LL long
	#define int long
	template<class T> using vec = vector<T>;
	using VB = vec<bool>;	using WB = vec<VB>;
	using VC = vec<char>;	using WC = vec<VC>;
	using VI = vec<int>;	using WI = vec<VI>;
	using VD = vec<double>;	using WD = vec<VD>;
	using VS = vec<string>;	using WS = vec<VS>;
	using PI = pair<int, int>;	using VPI = vec<PI>; using WPI = vec<VPI>;
	using MI = map<int, int>;	using VMI = vec<MI>;

bool debug;
#define _GLIBCXX_DEBUG
#define _LIBCPP_DEBUG 2
#define _LIBCPP_DEBUG2 2
#define ln << '\n'
#define tb << '\t'
#define sp << ' '
#define DD(x) if(debug) cerr << #x << " = " << (x) << ", "
#define DDD(x) if(debug) cerr << #x << " = " << (x) ln
#define db dd
#define dbg ddd

void settings();
void solve();

signed main(signed argc, char *argv[]) {
	#ifdef EBUG
		debug = true;
	#elif defined(ONLINE_JUDGE)
		debug = false;
	#else
		debug = argc >= 2;
	#endif
	if(!debug) {
		cin.tie(0);
		ios::sync_with_stdio(0);
	}
	cout << fixed << setprecision(20);
	cerr << fixed << setprecision(20);

	settings();
	solve();

	return 0;
}

/******************************* basic library ********************************/
/** structure **/
	template<class T> struct Graph { bool directed = false; int nv = -1; int ne = -1; vec<map<int,T>> e;
		Graph<T> rev() { if(not directed) return *this; Graph<T> g = *this; for(auto& ei : g.e) ei.clear(); times(nv, i) for(auto& p : e[i]) g.e[p.first][i] = p.second; return g; }
	};
	using GraphI = Graph<int>;
/** IO **/
	template<class T> inline istream& operator>>(istream& s, vec<T>& v) { for(auto&& p : v) s >> p; return s; }
	int INPUT_GRAPH_index_sub = 1, INPUT_GRAPH_cost = 0; bool INPUT_GRAPH_allow_empty = false;
	template<class T> inline istream& operator>>(istream& s, Graph<T>& g) {
		const int sub = INPUT_GRAPH_index_sub, cost = INPUT_GRAPH_cost, emptyp = INPUT_GRAPH_allow_empty;
		if(g.nv + emptyp <= 0 and g.ne + emptyp <= 0) { s >> g.nv >> g.ne; } g.e = VMI(g.nv);
		times(g.ne, i) { int x, y; T d = cost; s >> x >> y; if(!d) s >> d; g.e[x - sub][y - sub] = d; if(not g.directed) g.e[y - sub][x - sub] = d; } return s;
	}
	template<class T, class S> inline ostream& operator<<(ostream&, const pair<T, S>&);
	template<class T>          inline ostream& operator<<(ostream&, const vec<T>&);
	template<class T, class S> inline ostream& operator<<(ostream&, const map<T, S>&);
	template<class T> inline ostream& operator<<(ostream&, const Graph<T>&);
	#define DEFINE_ITER_OUTPUT(s, x, sep) { int i = 0; for(const auto& x##0_elem : x) { if(i++) s << sep; s << x##0_elem; } return s; }
	template<class T, class S> inline ostream& operator<<(ostream& s, const pair<T, S>& p) { return s << "(" << p.first << "," << p.second << ")"; }
	template<class T>          inline ostream& operator<<(ostream& s, const vec<T>& v) DEFINE_ITER_OUTPUT(s, v, ' ')
	template<class T, class S> inline ostream& operator<<(ostream& s, const map<T, S>& m) DEFINE_ITER_OUTPUT(s, m, ' ')
	template<class T>          inline ostream& operator<<(ostream& s, const vec<vec<T>>& w) DEFINE_ITER_OUTPUT(s, w, '\n')
	template<class T, class S> inline ostream& operator<<(ostream& s, const vec<map<T, S>>& vm) DEFINE_ITER_OUTPUT(s, vm, '\n')
	template<class T> inline ostream& operator<<(ostream& s, const Graph<T>& g) { return s << "Graph(nv:" << g.nv << " ne:" << g.ne << " e:[" ln << g.e ln << "])"; }
	inline void RD() {}
	template<class T, class...S> inline T& RD(T& t, S&... s) { cin >> t; RD(s...); return t; } /* returns first side */
	template<class T, class...S> inline vec<T>& RD(vec<T>& t, vec<S>&... s) { times(t.size(), i) { RD(t[i], s[i]...); } return t; }
	#define RR(typ, ...) typ __VA_ARGS__; RD(__VA_ARGS__)
	template<class T, class...A> inline T READ(A... a) { T t(a...); cin >> t; return t; }
	template<class T> inline void dddf(const T& t) { if(debug) cerr << t ln; }
	template<class T, class...U> inline void dddf(const T& t, const U&... u) { if(debug) { cerr << t << ", "; dddf(u...); }}
	#define ddd(...) if(debug) { cerr << #__VA_ARGS__ << " = "; dddf(__VA_ARGS__); }
/** container **/
	#define all(v) begin(v), end(v)
	template<class T> inline T max(const pair<T, T>& p) { return max(p.first, p.second); }
	template<class T> inline T min(const pair<T, T>& p) { return min(p.first, p.second); }
	template<class T> inline T max(const vec<T>& v) { return *max_element(all(v)); }
	template<class T> inline T min(const vec<T>& v) { return *min_element(all(v)); }
	template<class T> inline T sum(const vec<T>& v) { T s = v.empty() ? 0 : v[0]; uptil(1, v.size(), i) s += v[i]; return s; }
	template<class T> inline T sum(const vec<T>& v, int mod) { T s = v.empty() ? 0 : v[0]; uptil(1, v.size(), i) (s += v[i]) %= mod; return s; }
	template<class T, class U> inline T dig(const U& d, const T& t) { return t; }
	template<class T, class U, class...I> inline U dig(const U& d, const T& t, int i, I... j) {
		return 0 <= i && i < t.size() ? dig(d, t[i], j...) : d; }
	#define first_itr_st_val_ge_ lower_bound
	#define first_itr_st_val_gt_ upper_bound
/** other **/
	template<class T> inline signed SIZE(const T& t) { return t.size(); }
	#define size SIZE
	#define MP make_pair
	#define MT make_tuple
	#define b_max(x, y) x = max(x, y)
	#define b_min(x, y) x = min(x, y)
	inline LD AC(LD d) { return d ? d : 0; }
[[maybe_unused]] constexpr long INF = 1LL << 60;
[[maybe_unused]] constexpr long MOD = 1000000007; // 1000000009; // 998244353;

/****************************** optional library ******************************/
/* <sr.q.uf> */
	// VERIFIED: arc090b
	// ref: https://github.com/monyone/teihen_library/blob/master/DataStructure/01_WeightedUnionFind.md
	struct UnionFind {
		int n;
		VI parents, treeSizes, weightDiffs;
		UnionFind(int n_) : n(n_), parents(n), treeSizes(n, 1), weightDiffs(n, 0) { times(n, i) parents[i] = i; }
		int root(int i) {
			if(parents[i] == i) return i;
			int p = root(parents[i]);
			weightDiffs[i] += weightDiffs[parents[i]];
			return parents[i] = p;
		}
		int weight(int i) { root(i); return weightDiffs[i]; }
		void merge(int i, int j, int w) { // w > 0 if i < j
			if(same(i, j)) return;
			int x = w + weight(i) - weight(j);
			i = root(i); j = root(j);
			if(treeSizes[i] < treeSizes[j]) { swap(i, j); x = -x; }
			parents[j] = i;
			treeSizes[i] += treeSizes[j]; treeSizes[j] = -1;
			weightDiffs[j] = x;
		}
		bool same(int i, int j) { return root(i) == root(j); }
		int diff(int base, int i) { return same(base, i) ? weight(i) - weight(base) : -INF; }
	};
/* </sr.q.uf> */

/************************************ main ************************************/

void settings() {
	// INPUT_GRAPH_index_sub = 0;		// uncomment if input index is 0-based
	// INPUT_GRAPH_allow_empty = true;	// uncomment to allow empty graph
	// INPUT_GRAPH_no_cost = 1;			// uncomment if all input costs are 1
}

void solve() {
// NMN(A)
/* <foxy.memo-area> */
int N;int M;cin>>N;cin>>M;VI A(N);times(N,Ri_0){cin>>A[Ri_0];}
/* </foxy.memo-area> */
	UnionFind uf(N);
	times(M, i) {
		int X, Y; cin >> X >> Y;
		uf.merge(X, Y, 0);
	}
	map<int, VI> trees;
	times(N, i) {
		trees[uf.root(i)].push_back(A[i]);
	}
	if(size(trees) == 1) {
		cout << 0 ln;
		return;
	}
	int k = size(trees) - 2;
	int ans = 0;
	VI rest; rest.reserve(N);
	for(const auto& p : trees) {
		const VI& t = p.second;
		int m = INF, mi;
		times(size(t), i) if(t[i] < m) { m = t[i]; mi = i; }
		ans += m;
		times(size(t), i) if(i != mi) rest.push_back(t[i]);
	}
	sort(all(rest));
	ddd(ans, k, rest);
	if(size(rest) < k) { cout<<"Impossible" ln;return;}
	times(k, i) ans += rest[i];
	cout << ans ln;
}


Measured memory_bytes: 14464