#include<set>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<algorithm>
#include<iostream>
using namespace std;
int a[100010],fa[100010],N,M,x,y,cnt,now[100010],size[100010],p;
long long ans;
int read()
{
	static int x;
	static char ch;
	x = 0;
	for(ch=getchar();ch>'9'||ch<'0';ch=getchar());
	for(;ch>='0'&&ch<='9';ch=getchar()) x = x * 10 + ch - '0';
	return x;
}
int find(int x)
{
	return x == fa[x] ? x : fa[x] = find(fa[x]);
}
bool cmp(int x,int y)
{
	return a[x] < a[y];
}
void solve()
{
	for (int i = 1;i<=N;++i) now[i] = i,size[fa[i]]++;
	sort(now+1,now+1+N,cmp); 
	p = N;
	cnt*=2;
	for (int i = N;i>=1 && p>=cnt;--i) if (size[fa[now[i]]] > 1) ans-=a[now[i]],size[fa[now[i]]]--,p--;
	cout << ans << endl;
}
int main()
{
	N = read();M = read();
	for (int i = 1;i<=N;++i) a[i] = read(),fa[i]=i,ans+=a[i];
	for (int i = 1;i<=M;++i) 
	{
		x = read() + 1;y = read() + 1;
		fa[find(x)] = find(y);
	}
	for (int i = 1;i<=N;++i) if(find(i)==i) ++cnt;
	cnt--;
	if (cnt>(N>>1)) puts("Impossible");
	else if (!cnt) puts("0");
	else solve();
	return 0;
}