#include <bits/stdc++.h>
#define pi pair< int, pair< int,int > >
#define mp make_pair
using namespace std;

ifstream fin("ubuntzei.in");
ofstream fout("ubuntzei.out");

int n, m, k;
bool l[2001];
vector <pair <int, int> > v[2001];
priority_queue <pi, vector<pi>, greater<pi> > pq;

int Count(int mask)
{
    int ct = 0;
    for(int i = 1; i <= n; i++)
    {
        if(((1<<i)&mask))
            ct++;
    }
    return ct;
}

void Dijkstra()
{
    pq.push(mp(0, mp(1, 0)));

    while(!pq.empty())
    {
        int drum = pq.top().first;
        int nod = pq.top().second.first;
        int mask = pq.top().second.second;
        pq.pop();

        if(nod == n)
        {
            if(Count(mask) == k)
            {
                fout << drum;

                return;
            }
            continue;
        }
        for(int i = 0; i < v[nod].size(); i++)
        {
            int next, cost;
            next = v[nod][i].first;
            cost = v[nod][i].second;
            int new_mask = mask;
            if(l[next])
            {
                new_mask = (new_mask|(1<<next));

            }
            pq.push(mp(cost+drum, mp(next, new_mask)));

        }

    }


}

int main()
{
   fin >> n >> m;
   fin >> k;
   for(int i = 1; i <= k; i++)
   {
       int x;
       fin >> x;
       l[x] = 1;
   }
   for(int i = 1; i <= m; i++)
   {
       int a, b, c;
       fin >> a >> b >> c;
       v[a].push_back(mp(b, c));
       v[b].push_back(mp(a, c));
   }
    Dijkstra();
    return 0;
}