#include <fstream>
#include <iostream>
#include <queue>
#include <vector>
#include <tuple>
using namespace std;

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

int n, m, k;
vector<pair <int, int> > g[2005];
int prieteni[2005];
bool visited[4100][2005];

void citire() {
    fin >> n >> m >> k;
    int nod;
    for(int i = 1; i <= k; i++) {
        fin >> nod;
        prieteni[nod] = i;
    }
    int x, y, z;
    while(m--) {
        fin >> x >> y >> z;
        g[x].push_back({y, z});
        g[y].push_back({x, z});
    }
}

void solve() {
    priority_queue<tuple<int, int, int> >q;
    q.push(make_tuple(0, 0, 1));
    while(!q.empty()) {
        int dist = -get<0>(q.top());
        int mask = -get<1>(q.top());
        int lastNode = get<2>(q.top());
        q.pop();
        //cout << dist << ' ' << mask << ' ' << lastNode << '\n';

        if(lastNode == n && mask == ( (1 << k )- 1) ) {
            fout << dist;
            return;
        }

        if(visited[mask][lastNode]) continue;
        visited[mask][lastNode] = true;

        for(int i = 0; i < g[lastNode].size(); i++) {
            int newMask = mask;
            if(prieteni[g[lastNode][i].first])
                newMask |= (1 << (prieteni[g[lastNode][i].first]-1));

            q.push(make_tuple(-dist-g[lastNode][i].second, -newMask, g[lastNode][i].first));
        }
    }
}

int main() {
    citire();
    solve();
}