/**
 * code generated by JHelper
 * More info: https://github.com/AlexeyDmitriev/JHelper
 * @author majk
 */

#ifndef MAJK_LIB
#define MAJK_LIB

#include <vector>
#include <stack>
#include <iostream>
#include <unordered_map>
#include <unordered_set>
#include <map>
#include <iomanip>
#include <set>
#include <functional>
#include <fstream>
#include <algorithm>
#include <cassert>
#include <cmath>
#include <string>
#include <sstream>
#include <queue>
#include <bitset>
using namespace std;

#define x first
#define y second
typedef std::pair<int,int> pii; typedef long long ll; typedef unsigned long long ull; typedef unsigned int ui; typedef pair<ui,ui> puu;

template <typename T, typename U> std::istream&operator>>(std::istream&i, pair<T,U>&p) {i >> p.x >> p.y; return i;}
template<typename T>std::istream&operator>>(std::istream&i,vector<T>&t) {for(auto&v:t){i>>v;}return i;}
template<typename T>std::ostream&operator<<(std::ostream&o,const vector<T>&t) {if(t.empty())o<<'\n';for(size_t i=0;i<t.size();++i){o<<t[i]<<" \n"[i == t.size()-1];}return o;}
template <typename T, typename U> std::ostream&operator<<(std::ostream&o, pair<T,U>&p) {o << p.x << ' ' << p.y; return o;}
template<typename T> using minheap = priority_queue<T, vector<T>, greater<T>>;
template<typename T> using maxheap = priority_queue<T, vector<T>, less<T>>;
auto fraclt = [](const pii&a,const pii&b) { return (ll)a.x * b.y < (ll)b.x * a.y; };
struct cmpfrac { bool operator()(const pii&a,const pii&b)const { return (ll)a.x * b.y < (ll)b.x * a.y; }};
template <typename T> bool in(T a, T b, T c) { return a <= b && b < c; }
ui logceil(int x) { return 8*sizeof(int)-__builtin_clz(x); }

namespace std {
    template<typename T,typename U>struct hash<pair<T,U>>{hash<T>t;hash<U>u;size_t operator()(const pair<T,U>&p)const{return t(p.x)^(u(p.y)<<7);}};
}
template<typename T,typename F>T bsh(T l,T h,const F&f){T r=-1,m;while(l<=h){m=(l+h)/2;if(f(m)){l=m+1;r=m;}else{h=m-1;}}return r;}
template<typename F> double bshd(double l,double h,const F&f,double p=1e-9){ui r=3+(ui)log2((h-l)/p);while(r--){double m=(l+h)/2;if(f(m)){l=m;}else{h=m;}}return (l+h)/2;}
template<typename T,typename F>T bsl(T l,T h,const F&f){T r=-1,m;while(l<=h){m=(l+h)/2;if(f(m)){h=m-1;r=m;}else{l=m+1;}}return r;}
template<typename F> double bsld(double l,double h,const F&f,double p=1e-9){ui r=3+(ui)log2((h-l)/p);while(r--){double m=(l+h)/2;if(f(m)){h=m;}else{l=m;}}return (l+h)/2;}
template<typename T> T gcd(T a,T b) { if (a<b) swap(a,b); return b?gcd(b,a%b):a; }

template<typename T>class vector2:public vector<vector<T>>{public:vector2(){} vector2(size_t a,size_t b,T t=T()):vector<vector<T>>(a,vector<T>(b,t)){}};
template<typename T>class vector3:public vector<vector2<T>>{public:vector3(){} vector3(size_t a,size_t b,size_t c,T t=T()):vector<vector2<T>>(a,vector2<T>(b,c,t)){}};
template<typename T>class vector4:public vector<vector3<T>>{public:vector4(){} vector4(size_t a,size_t b,size_t c,size_t d,T t=T()):vector<vector3<T>>(a,vector3<T>(b,c,d,t)){}};
template<typename T>class vector5:public vector<vector4<T>>{public:vector5(){} vector5(size_t a,size_t b,size_t c,size_t d,size_t e,T t=T()):vector<vector4<T>>(a,vector4<T>(b,c,d,e,t)){}};
template <typename T> struct bounded_priority_queue {
	inline bounded_priority_queue(ui X) : A(X), B(0) {}
	inline void push(ui L, T V) { B = max(B, L); A[L].push(V); }
	inline const T &top() const { return A[B].front(); }
	inline void pop() { A[B].pop(); while (B > 0 && A[B].empty()) --B; }
	inline bool empty() const { return A[B].empty(); }
	inline void clear() { B = 0; for (auto &a: A) a = queue<T>(); }
private:
	vector<queue<T>> A; ui B;
};


#endif


struct UnionFind {
	UnionFind(size_t N) : P(N, -1), comp(N) {}
	int find(int x) { while (P[x]>=0){x = P[x];}return x; }
	bool united(int x, int y) { return find(x) == find(y); }
	bool unite(int x, int y) { x=find(x);y=find(y);if(x==y){return false;}--comp;if(P[x]>P[y]){swap(x,y);}P[x]+=P[y];P[y]=x;return true;}
	vector<int> P;
	size_t comp;
};

/** Product of two 64-bit numbers modulo another. */
ull mulull(ull a, ull z, ull mod) {
#ifdef __SIZEOF_INT128__
	__int128 result = ((__int128) a * (__int128) z) % (__int128) mod;
	return (ull) result;
#else
    // schrage method
	ull q = mod / a, r = mod % a;
	ull rzq = (r < q) ? r * (z/q) : mulull(r, z/q, mod);
	ull azq = a * (z % q);
	if (azq >= rzq) return azq-rzq; else return azq-rzq+mod;
#endif
}

/** Multiply two 64-bit unsigned integers to get a 128-bit unsigned integer (as a pair of ull) */
pair<ull,ull> mulull(ull a, ull b) {
#ifdef __SIZEOF_INT128__
	__int128 result = (__int128) a * (__int128) b;
	return {(ull) (result >> 64), (ull) result};
#else
	ull c = (ui)a, d = a>>32, e = (ui)b, f = b>>32, g = d*f, h = d*e, i = f*c, j = c*e, k = (j>>32)+(ui)h+(ui)i, l = g+(h>>32)+(i>>32)+(k>>32);
	return {l, ((h+i) << 32) + j};
#endif
}

bool fractionGreaterOrEqual(ll a, ll b, ll c, ll d) {
	if (b < 0) { b = -b; a = -a; }
	if (d < 0) { d = -d; c = -c; }
	return a < 0 && c < 0 ? mulull(-a, d) <= mulull(-c, b) : (a >= 0) && (c < 0 || mulull(a, d) >= mulull(c, b));
}

bool fractionGreaterOrEqual(double a, double b, double c, double d) {
	return a/b >= c/d;
}

// this is based on modulus, but it's 2-3 times slower than the former
//bool fractionGreaterOrEqual(ll a, ll b, ll c, ll d) {
//	if (a<0 && c<0) return greaterOrEqual(-c,d,-a,b);
//	if (a<0) return false;
//	if (c<0) return true;
//	if (b==0) return true;
//	if (d==0) return false;
//	ll ab = a/b, cd = c/d;
//	if (ab > cd) return true;
//	if (ab < cd) return false;
//	return !greaterOrEqual(b, a%b, d, c%d);
//}


/** Computing lower and upper envelope. Useful for "convex hull trick". */
namespace Envelope {
	template<typename T>
	struct Line {
		T m, b;
		mutable function<const Line<T> *()> succ;

		bool operator<(const Line &rhs) const {
			if (rhs.b != numeric_limits<T>::min()) return m < rhs.m;
			const Line *s = succ();
			if (!s) return 0;
			return b - s->b < (s->m - m) * rhs.m;
		}
	};

	template<typename T>
	struct Upper : public multiset<Envelope::Line<T>> {
		using parent = multiset<Line<T>>;

		bool bad(typename parent::iterator y) {
			auto z = next(y);
			if (y == parent::begin()) {
				return z != parent::end() && y->m == z->m && y->b <= z->b;
			} else {
				auto x = prev(y);
				if (z == parent::end()) {
					return y->m == x->m && y->b <= x->b;
				} else {
					return fractionGreaterOrEqual(x->b - y->b, y->m - x->m, y->b - z->b, z->m - y->m);
				}
			}
		}

		void insert_line(T m, T b) {
			auto y = parent::insert({m, b});
			y->succ = [=] { return next(y) == parent::end() ? 0 : &*next(y); };
			if (bad(y)) { parent::erase(y); return; }
			while (next(y) != parent::end() && bad(next(y))) parent::erase(next(y));
			while (y != parent::begin() && bad(prev(y))) parent::erase(prev(y));
		}

		T operator[](T x) const {
			auto l = parent::lower_bound({x, numeric_limits<T>::min()});
			return l == parent::end() ? numeric_limits<T>::min() : l->m * x + l->b;
		}
	};

	template<typename T>
	struct Lower : public Upper<T> {
		void insert_line(T m, T b) { Upper<T>::insert_line(-m, -b); }
		T operator[](T x) const { return -Upper<T>::operator[](x); }
	};
}

class D {
public:
    void solve(istream& cin, ostream& cout) {
        int N, M; cin >> N >> M;
        if (N-1-M > N/2) {
            cout << "Impossible\n";
            return;
        }
        if (M == N-1) {
            cout << 0 << endl;
            return;
        }

        vector<int> A(N); cin >> A;
        UnionFind U(N);
        for (int i = 0; i < M; ++i) {
            int a,b; cin >> a >> b;
            U.unite(a,b);
        }

        map<int, vector<int>> Z;
        for (int i = 0; i < N; ++i) {
            Z[U.find(i)].push_back(A[i]);
        }

        vector<int> Q;
        ll ans = 0;
        for (auto &z:Z) {
            sort(z.y.begin(),z.y.end());
            ans += z.y[0];
            copy(z.y.begin()+1, z.y.end(), back_inserter(Q));
        }

        sort(Q.begin(),Q.end());
        for (int i = 0; i < Z.size()-2; ++i) ans += Q[i];
        cout << ans << endl;
    }
};


int main() {
	ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
	D solver;
	std::istream& in(std::cin);
	std::ostream& out(std::cout);
	solver.solve(in, out);
    return 0;
}


Measured memory_bytes: 7040