// Slower C++ solution:
#include<cstdio>

#include<cstring>

#include<algorithm>

#include<queue>

#define mp(x,y) make_pair(x,y) 

#define ll long long

#define MN 200005

using namespace std;

inline ll in(){

    ll x=0;bool f=0;char c;

    for (;(c=getchar())<'0'||c>'9';f=c=='-');

    for (x=c-'0';(c=getchar())>='0'&&c<='9';x=(x<<3)+(x<<1)+c-'0');

    return f?-x:x;

}

typedef pair<ll,int> pr;

//priority_queue<pr,vector<pr>,greater<pr> >q;

priority_queue<ll,vector<ll>,greater<ll> >q;

struct edge{

	int to,nxt;

}e[MN<<1];

ll a[MN],res;

int d[MN],fa[MN],rk[MN],num[MN],h[MN],ch[2][MN];

int n,m,x,y,cnt,tot,fx,fy,rt,ct;

bool vis[MN];

ll mn[MN];bool tmp[MN];

inline int gf(int x){return fa[x]?fa[x]=gf(fa[x]):x;}

inline void ins(int x,int y){

	e[++cnt].to=y;e[cnt].nxt=h[x];h[x]=cnt;

}

inline void dfs(int u){

	mn[tot]=min(mn[tot],a[u]);

	for (int i=h[u];i;i=e[i].nxt){

		int v=e[i].to;

		if (vis[v]) continue;

		vis[v]=1;num[v]=tot;dfs(v);

	}

}

inline int merge(int x,int y){

    if (!x) return y;if (!y) return x;

    if (a[x]>a[y]||(a[x]==a[y]&&x>y)) swap(x,y);

    ch[1][x]=merge(ch[1][x],y);fa[ch[1][x]]=x;

    if (d[ch[0][x]]<d[ch[1][x]]) swap(ch[0][x],ch[1][x]);

    d[x]=d[ch[1][x]]+1;return x;

}

inline int pop(int x){

    a[x]=-1;fa[x]=-1;fa[ch[0][x]]=fa[ch[1][x]]=0;

    return merge(ch[0][x],ch[1][x]);

}

int main()

{

	n=in();m=in();

	memset(mn,0x3f,sizeof(mn));

	for (int i=1;i<=n;++i) a[i]=in();

	for (int i=1;i<=m;++i){

		x=in()+1;y=in()+1;

		ins(x,y);ins(y,x);

	}

	for (int i=1;i<=n;++i)

	if (!vis[i]){

		vis[i]=1;num[i]=(++tot);

		rk[tot]=i;dfs(i);

	}

	if (tot==1) {printf("0");return 0;}

	for (int i=1;i<=tot;++i) res+=1ll*mn[i];

	for (int i=1;i<=n;++i){

		if (!tmp[num[i]]&&a[i]==mn[num[i]]) {tmp[num[i]]=1;continue;}

		else q.push(a[i]);

	}

	while (!q.empty()){

		if (ct==tot-2) break;

		ll x=q.top();q.pop();++ct;res+=1ll*x;

	} 

	if (ct==tot-2) printf("%lld",res);else printf("Impossible");

	/*

	for (int i=1;i<=n;++i){

		if (rk[num[i]]==i) continue;

		fx=gf(i),fy=gf(rk[num[i]]);merge(fx,fy);

	}

	for (int i=1;i<=tot;++i){

		fx=gf(rk[i]);q.push(mp(a[fx],fx));

	}

	while (!q.empty()){

		pr x=q.top();q.pop();

		if (q.empty()) break;pr y=q.top();q.pop();

		res+=1ll*x.first+y.first;++ct;

		fx=gf(x.second),fy=gf(y.second);printf("%d %d\n",fx,fy);

		fx=pop(fx);fy=pop(fy);rt=merge(fx,fy);

		if (rt) q.push(mp(a[rt],rt));

	}*/

//	if (ct+m!=n-1) printf("Impossible");

//	else 

//	printf("%lld",res);

	return 0;

}

// Faster C++ solution for the same problem (measured speedup: 2.526857801462526x):
#include <bits/stdc++.h>

using namespace std;



#define ll long long

#define sd(x) scanf("%d", &(x))

#define pii pair<int, int>

#define F first

#define S second

#define all(c) ((c).begin()), ((c).end())

#define sz(x) ((int)(x).size())

#define ld long double



template<class T,class U>

ostream& operator<<(ostream& os,const pair<T,U>& p){

	os<<"("<<p.first<<", "<<p.second<<")";

	return os;

}



template<class T>

ostream& operator <<(ostream& os,const vector<T>& v){

	os<<"{";

	for(int i = 0;i < (int)v.size(); i++){

		if(i)os<<", ";

		os<<v[i];

	}

	os<<"}";

	return os;

}



#ifdef LOCAL

#define cerr cout

#else

#endif



#define TRACE



#ifdef TRACE

#define trace(...) __f(#__VA_ARGS__, __VA_ARGS__)

template <typename Arg1>

void __f(const char* name, Arg1&& arg1){

	cerr << name << " : " << arg1 << std::endl;

}

template <typename Arg1, typename... Args>

void __f(const char* names, Arg1&& arg1, Args&&... args){

	const char* comma = strchr(names + 1, ',');cerr.write(names, comma - names) << " : " << arg1<<" | ";__f(comma+1, args...);

}

#else

#define trace(...)

#endif



struct dsu{

    int n;

    vector<int> par;

    vector<vector<int>> comp;

    int num;

    dsu(int n) : n(n), par(n), comp(n), num(n){

        iota(par.begin(), par.end(), 0);

    }

    int root(int x){

        return x == par[x] ? x : (par[x] = root(par[x]));

    }

    bool merge(int x, int y){

        x = root(x); y = root(y);

        if(x == y) return 0;

        par[x] = y;

        num--;

        return 1;

    }

    void get(){

        for(int i = 0; i < n; i++) comp[root(i)].push_back(i);

    }

};





int a[100005];

int main(){

    int n, m; sd(n); sd(m);

    for(int i = 0; i < n; i++) sd(a[i]);

    dsu D(n);

    for(int i = 0; i < m; i++){

        int u, v;

        sd(u); sd(v);

        D.merge(u, v);

    }

    if(D.num == 1){

        printf("0\n");

        return 0;

    }

    D.get();

    vector<int> rem;

    ll ans = 0;

    int num = 0;

    for(int i = 0; i < n; i++) if(!D.comp[i].empty()){

        vector<int> V = D.comp[i];

        sort(all(V), [&](int i, int j){

            return a[i] < a[j];

        });

        ans += a[V[0]];

        for(int j = 1; j < sz(V); j++) rem.push_back(a[V[j]]);

    }

    if(sz(rem) < D.num - 2){

        printf("Impossible\n");

        return 0;

    }

    sort(all(rem));

    for(int i = 0; i < D.num - 2; i++) ans += rem[i];

    printf("%lld\n", ans);

}