using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.IO;
using System.Text;
using System.Globalization;
using System.Diagnostics;



class Myon
{
    public Myon() { }
    public static int Main()
    {
        new Myon().calc();
        return 0;
    }


    Scanner cin;


    int N, M;
    int[] A;

    void calc()
    {
        cin = new Scanner();
        N = cin.nextInt();
        M = cin.nextInt();
        init(N);

        A = cin.ArrayInt(N);
        int[] x = new int[M];
        int[] y = new int[M];
        for (int i = 0; i < M; i++)
        {
            x[i] = cin.nextInt();
            y[i] = cin.nextInt();
            connect(x[i], y[i]);
        }
        bool[] used = new bool[N];
        int group = 0;
        long ans = 0;
        for (int i = 0; i < N; i++)
        {
            if(uni[i] < 0)
            {
                ans += A[low[i]];
                group++;
                used[low[i]] = true;
            }
        }
        
        if(group == 1)
        {
            Console.WriteLine(0);
            return;
        }
        int need = group - 2;
        List<int> l = new List<int>();
        for (int i = 0; i < N; i++)
        {
            if (!used[i])
            {
                l.Add(A[i]);
            }
        }
        l.Sort();
        if(l.Count < need)
        {
            Console.WriteLine("Impossible");
            return;
        }

        for (int i = 0; i < need; i++)
        {
            ans += l[i];
        }
        Console.WriteLine(ans);
    }

    int[] uni;
    int[] low;
    void init(int N)
    {
        uni = new int[N];
        low = new int[N];
        for (int i = 0; i < N; i++)
        {
            uni[i] = -1;
            low[i] = i;
        }
    }

    int root(int a)
    {
        if (uni[a] < 0) return a;
        else return uni[a] = root(uni[a]);
    }

    bool connect(int a, int b)
    {
        a = root(a);
        b = root(b);
        if (a == b) return false;
        if (uni[a] > uni[b]) swap(ref a, ref b);
        uni[a] += uni[b];
        if (A[low[a]] > A[low[b]]) low[a] = low[b];
        uni[b] = a;
        return true;
    }

    void swap<T>(ref T a, ref T b)
    {
        T c = a;
        a = b;
        b = c;
    }  
}


class Scanner
{
    string[] s;
    int i;

    char[] cs = new char[] { ' ' };

    public Scanner()
    {
        s = new string[0];
        i = 0;
    }

    public string next()
    {
        if (i < s.Length) return s[i++];
        string st = Console.ReadLine();
        while (st == "") st = Console.ReadLine();
        s = st.Split(cs, StringSplitOptions.RemoveEmptyEntries);
        if (s.Length == 0) return next();
        i = 0;
        return s[i++];
    }

    public int nextInt()
    {
        return int.Parse(next());
    }
    public int[] ArrayInt(int N, int add = 0)
    {
        int[] Array = new int[N];
        for (int i = 0; i < N; i++)
        {
            Array[i] = nextInt() + add;
        }
        return Array;
    }

    public long nextLong()
    {
        return long.Parse(next());
    }

    public long[] ArrayLong(int N, long add = 0)
    {
        long[] Array = new long[N];
        for (int i = 0; i < N; i++)
        {
            Array[i] = nextLong() + add;
        }
        return Array;
    }

    public double nextDouble()
    {
        return double.Parse(next());
    }


    public double[] ArrayDouble(int N, double add = 0)
    {
        double[] Array = new double[N];
        for (int i = 0; i < N; i++)
        {
            Array[i] = nextDouble() + add;
        }
        return Array;
    }
}


Measured memory_bytes: 30924