using System;
using System.Linq;
using System.Linq.Expressions;
using System.Collections.Generic;
using Debug = System.Diagnostics.Debug;
using StringBuilder = System.Text.StringBuilder;
using System.Numerics;
using Point = System.Numerics.Complex;
using Number = System.Int32;
namespace Program
{
    public class Solver
    {
        public void Solve()
        {
            var n = sc.Integer();
            var m = sc.Integer();
            var k = sc.Integer();
            var g = new SteinerTreeMaker(n);
            for (int i = 0; i < m; i++)
            {
                var f = sc.Integer() - 1;
                var t = sc.Integer() - 1;
                var c = sc.Integer();
                g.AddEdge(f, t, c);
            }
            for (int i = 0; i < k; i++)
                g.AddVertex(sc.Integer() - 1);
            IO.Printer.Out.WriteLine(g.Get());


        }
        public IO.StreamScanner sc = new IO.StreamScanner(Console.OpenStandardInput());
        static T[] Enumerate<T>(int n, Func<int, T> f) { var a = new T[n]; for (int i = 0; i < n; ++i) a[i] = f(i); return a; }
        static public void Swap<T>(ref T a, ref T b) { var tmp = a; a = b; b = tmp; }
    }
}
#region main
static class Ex
{
    static public string AsString(this IEnumerable<char> ie) { return new string(System.Linq.Enumerable.ToArray(ie)); }
    static public string AsJoinedString<T>(this IEnumerable<T> ie, string st = " ") { return string.Join(st, ie); }
    static public void Main()
    {
        var solver = new Program.Solver();
        solver.Solve();
        Program.IO.Printer.Out.Flush();
    }
}
#endregion
#region Ex
namespace Program.IO
{
    using System.IO;
    using System.Text;
    using System.Globalization;
    public class Printer : StreamWriter
    {
        static Printer() { Out = new Printer(Console.OpenStandardOutput()) { AutoFlush = false }; }
        public static Printer Out { get; set; }
        public override IFormatProvider FormatProvider { get { return CultureInfo.InvariantCulture; } }
        public Printer(System.IO.Stream stream) : base(stream, new UTF8Encoding(false, true)) { }
        public Printer(System.IO.Stream stream, Encoding encoding) : base(stream, encoding) { }
        public void Write<T>(string format, T[] source) { base.Write(format, source.OfType<object>().ToArray()); }
        public void WriteLine<T>(string format, T[] source) { base.WriteLine(format, source.OfType<object>().ToArray()); }
    }
    public class StreamScanner
    {
        public StreamScanner(Stream stream) { str = stream; }
        public readonly Stream str;
        private readonly byte[] buf = new byte[1024];
        private int len, ptr;
        public bool isEof = false;
        public bool IsEndOfStream { get { return isEof; } }
        private byte read()
        {
            if (isEof) return 0;
            if (ptr >= len) { ptr = 0; if ((len = str.Read(buf, 0, 1024)) <= 0) { isEof = true; return 0; } }
            return buf[ptr++];
        }
        public char Char() { byte b = 0; do b = read(); while ((b < 33 || 126 < b) && !isEof); return (char)b; }

        public string Scan()
        {
            var sb = new StringBuilder();
            for (var b = Char(); b >= 33 && b <= 126; b = (char)read())
                sb.Append(b);
            return sb.ToString();
        }
        public string ScanLine()
        {
            var sb = new StringBuilder();
            for (var b = Char(); b != '\n'; b = (char)read())
                if (b == 0) break;
                else if (b != '\r') sb.Append(b);
            return sb.ToString();
        }
        public long Long()
        {
            if (isEof) return long.MinValue;
            long ret = 0; byte b = 0; var ng = false;
            do b = read();
            while (b != 0 && b != '-' && (b < '0' || '9' < b));
            if (b == 0) return long.MinValue;
            if (b == '-') { ng = true; b = read(); }
            for (; true; b = read())
            {
                if (b < '0' || '9' < b)
                    return ng ? -ret : ret;
                else ret = ret * 10 + b - '0';
            }
        }
        public int Integer() { return (isEof) ? int.MinValue : (int)Long(); }
        public double Double() { var s = Scan(); return s != "" ? double.Parse(s, CultureInfo.InvariantCulture) : double.NaN; }
        private T[] enumerate<T>(int n, Func<T> f)
        {
            var a = new T[n];
            for (int i = 0; i < n; ++i) a[i] = f();
            return a;
        }

        public char[] Char(int n) { return enumerate(n, Char); }
        public string[] Scan(int n) { return enumerate(n, Scan); }
        public double[] Double(int n) { return enumerate(n, Double); }
        public int[] Integer(int n) { return enumerate(n, Integer); }
        public long[] Long(int n) { return enumerate(n, Long); }
    }
}
#endregion
#region Edge
public struct Edge : IComparable<Edge>
{
    public int from, to;
    public int cost;
    public Edge(int f, int t, int v) : this() { from = f; to = t; cost = v; }
    public int CompareTo(Edge other)
    {
        return cost.CompareTo(other.cost);
    }
}
#endregion
public class SteinerTreeMaker
{
    int n;
    int[][] g;
    List<int> s;
    List<int> es;
    const int INF = 1000000000;
    public SteinerTreeMaker(int n)
    {
        this.n = n;
        g = new int[n][];
        s = new List<int>();
        es = new List<int>();
        for (int i = 0; i < n; i++)
            g[i] = new int[n];
        for (int i = 0; i < n; i++)
            for (int j = 0; j < n; j++)
                if (i != j) g[i][j] = INF;
    }
    public void AddEdge(int f, int t, int c)
    {
        g[f][t] = Math.Min(g[f][t], c);
        g[t][f] = Math.Min(g[t][f], c);
        es.Add(t + f * 128 + 128 * 128 * c);
    }
    public void AddVertex(int v)
    {
        s.Add(v);
    }
    bool ok = false;
    public void Build()
    {
        s = s.Distinct().ToList(); s.Sort();
        for (int k = 0; k < n; k++)
            for (int i = 0; i < n; i++)
                for (int j = 0; j < n; j++)
                    g[i][j] = Math.Min(g[i][j], g[i][k] + g[k][j]);
        es.Sort();
        ok = true;
    }
    public long Get()
    {
        if (!ok) Build();
        var k = s.Count;
        if (k <= 15) return GetKSmall();
        return GetKLarge();
    }
    /// <summary>
    /// O(n*3^k+n^2*2^k+n^3)
    /// </summary>
    /// <returns></returns>
    long GetKSmall()
    {
        var k = s.Count;
        if (k <= 1) return 0;
        var opt = new int[1 << k][];
        for (int i = 0; i < 1 << k; i++)
        {
            opt[i] = new int[n];
            for (int j = 0; j < n; j++)
                opt[i][j] = INF;
        }
        for (int i = 0; i < k; i++)
            for (int j = 0; j < n; j++)
                opt[1 << i][j] = g[s[i]][j];

        for (int i = 1; i < 1 << k; i++)
        {
            if ((i & (i - 1)) == 0) continue;
            {
                for (var sub = i; sub != 0; sub = (sub - 1) & i)
                    for (int p = 0; p < n; p++)
                        opt[i][p] = Math.Min(opt[i][p], opt[sub][p] + opt[i - sub][p]);
            }
            for (int p = 0; p < n; p++)
                for (int q = 0; q < n; q++)
                    opt[i][p] = Math.Min(opt[i][p], opt[i][q] + g[p][q]);
        }
        long ans = long.MaxValue;
        for (int i = 0; i < 1 << k; i++)
            for (int j = 0; j < n; j++)
                ans = Math.Min(ans, opt[i][j] + opt[((1 << k) - 1) - i][j]);
        return ans;
    }
    public long GetKLarge()
    {
        var rem = new List<int>();
        for (int i = 0; i < n; i++)
        {
            if (!s.Contains(i)) rem.Add(i);
        }
        var k = rem.Count;
        long ans = long.MaxValue;
        var ea = es.ToArray();
        var root = s[0];
        for (int i = 0; i < 1 << k; i++)
        {
            var use = new bool[n];
            foreach (var x in s) use[x] = true;
            for (int j = 0; j < k; j++) if ((i >> j & 1) == 1) use[rem[j]] = true;
            var set = new DisjointSet(n);
            long val = 0;
            var cnt = -1;
            for (int j = 0; j < n; j++) if (use[j]) cnt++;
            foreach (var e in ea)
            {
                if (cnt == 0) break;
                var f = e % 128;
                var t = (e / 128) % 128;
                var c = e / (128 * 128);

                if (use[f] && use[t])
                {
                    if (set.Unite(f, t))
                    {
                        val += c;
                        cnt--;
                    }
                }
            }
            if (cnt == 0)
                ans = Math.Min(ans, val);

        }
        return ans;
    }
}
#region DisjointSet
public class DisjointSet
{
    public int[] par, ranks;
    public DisjointSet(int n)
    {
        par = new int[n];
        for (int i = 0; i < n; i++)
            par[i] = i;
        ranks = new int[n];
    }
    public int this[int id] { get { return (par[id] == id) ? id : this[par[id]]; } }
    public bool Unite(int x, int y)
    {
        x = this[x]; y = this[y];
        if (x == y) return false;
        if (ranks[x] < ranks[y])
            par[x] = y;
        else
        {
            par[y] = x;
            if (ranks[x] == ranks[y])
                ranks[x]++;
        }
        return true;
    }
    public bool IsUnited(int x, int y) { return this[x] == this[y]; }

}
#endregion