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

vector<int> q,sq,e[100010];
int a[100010];
bool v[100010];

void dfs(int x) {
	v[x] = true;
	if (q.empty() || a[x] >= q[0]) q.push_back(a[x]);
	else {
		q.push_back(q[0]);
		q[0] = a[x];
	}
	for (int i = 0; i < e[x].size(); i++) 
		if (!v[e[x][i]]) dfs(e[x][i]);
}

int main() {
	int n,m;
	scanf("%d%d",&n,&m);
	for (int i = 0; i < n; i++) scanf("%d",&a[i]);
	
	while (m--) {
		int x,y;
		scanf("%d%d",&x,&y);
		e[x].push_back(y);
		e[y].push_back(x);
	}
	
	long long ans = 0, tot = 0;
	for (int i = 0; i < n; i++) if (!v[i]) {
		tot++;
		dfs(i);
		ans += q[0];
		for (int i = 1; i < q.size(); i++) sq.push_back(q[i]);
		q.clear();
	}
	
	if (tot < 2) {
		printf("0\n");
		return 0;	
	}
	
	if (sq.size() < tot - 2) {
		printf("Impossible\n");
		return 0;
	}
	
	sort(sq.begin(),sq.end());
	for (int i = 0; i < tot - 2; i++) ans += sq[i];
	printf("%lld\n",ans);
}