#include <fstream>
#include <queue>
#include <vector>
#include <algorithm>
#define v first
#define c second
using namespace std;

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

const int maxn = 2013;
const int inf = 0x7fffffff;
int N, M, K, x, y, c;
typedef pair<int, int> vecin;
vector<vecin> vecini[maxn]; // Lista vecinilor fiecarui nod
int dist[maxn];             // Distantele
vector<int> prieteni;       // Losta prietenilor
struct cmp {
    bool operator() (const int& a, const int& b) {
        return dist[a] > dist[b];
    }
};
bool comp(const int& a, const int& b) { return dist[a] < dist[b]; }
priority_queue<int, vector<int>, cmp> qu;  // Coada de prioritati

void dijkstra(int beg, int end)
{
    fill(dist+1, dist+N+1, inf);
    dist[beg] = 0;
    qu.push(beg);
    int here = 0;
    while (!qu.empty() && here != end)
    {
        here = qu.top(); qu.pop();
        for (int i = 0; i < vecini[here].size(); i++)
        {
            vecin vec = vecini[here][i];
            if (dist[here] + vec.c < dist[vec.v])
            {
                dist[vec.v] = dist[here] + vec.c;
                qu.push(vec.v);
            }
        }
    }
}

int main()
{
    in >> N >> M >> K;
    for (int i = 0; i < K; i++) { in >> x; prieteni.push_back(x); }
    for (int i = 0; i < M; i++)
    {
        in >> x >> y >> c;
        vecini[x].push_back(make_pair(y, c));
        vecini[y].push_back(make_pair(x, c));
    }
    dijkstra(1, N);
    sort(prieteni.begin(), prieteni.end(), comp);
    int i; int mini = dist[prieteni[0]];
    for (i = 0; i < prieteni.size()-1; i++)
    {
        dijkstra(prieteni[i], prieteni[i+1]);
        mini += dist[prieteni[i+1]];
    }
    dijkstra(prieteni[i], N);
    mini += dist[N];
    out << mini;
    return 0;
}