#include <bits/stdc++.h>
using namespace std;
int n, m;
int w[100020];
int v[100020];
vector<int> a[100020];
int bestvalue;
int bestindex;
long long ans;
void dfs(int x) {
	v[x] = 1;
	if (bestvalue > w[x]) {
		bestvalue = w[x];
		bestindex = x;
	}
	for (int i: a[x]) {
		if (!v[i]) {
			dfs(i);
		}
	}
}
int main() {
	scanf("%d%d", &n, &m);
	for (int i = 0; i < n; i++) {
		scanf("%d", &w[i]);
	}
	for (int i = 0; i < m; i++) {
		int x, y;
		scanf("%d%d", &x, &y);
		a[x].push_back(y);
		a[y].push_back(x);
	}
	int cnt = 0;
	for (int i = 0; i < n; i++) {
		if (!v[i]) {
			bestvalue = 2e9;
			bestindex = -1;
			dfs(i);
			cnt++;
			ans += bestvalue;
			w[bestindex] = 2e9;
		}
	}
	sort(w, w + n);
	if (cnt == 1) {
		printf("0\n");
		exit(0);
	}
	for (int i = 0; i < cnt - 2; i++) {
		if (w[i] == 2e9) {
			printf("Impossible\n");
			exit(0);
		}
		ans += w[i];
	}
	printf("%lld\n", ans);
	return 0;
}