#include <bits/stdc++.h>
using namespace std;

using edge = tuple<int, int, int>;

int main()
{
    int n, m, k;
    cin >> n >> m >> k;
    vector<bool> must(m);
    for (int i = 0; i < k; i++)
    {
        int r;
        cin >> r;
        r--;
        must.at(r) = true;
    }
    const int s = 1 << k;
    map<pair<int, int>, int> r_idx;
    vector<pair<int, int>> to[n];
    int idx = 0;
    for (int i = 0; i < m; i++)
    {
        int a, b, c;
        cin >> a >> b >> c;
        a--;
        b--;
        to[a].emplace_back(b, c);
        to[b].emplace_back(a, c);
        if (must.at(i))
        {
            idx++;
            r_idx[{a, b}] = idx;
            r_idx[{b, a}] = idx;
        }
    }
    vector dist(n, vector<int>(s, 2e9));
    priority_queue<edge, vector<edge>, greater<edge>> q;
    q.emplace(0, 0, 0);
    while (not q.empty())
    {
        auto [d0, v, seen] = q.top();
        q.pop();
        if (d0 >= dist.at(v).at(seen))
        {
            continue;
        }
        dist.at(v).at(seen) = d0;
        for (auto &&[c, d_edge] : to[v])
        {
            int seen_new = seen;
            if (r_idx[{v, c}])
            {
                seen_new |= 1 << (r_idx[{v, c}] - 1);
            }
            if (d0 + d_edge >= dist.at(c).at(seen_new))
            {
                continue;
            }
            q.emplace(d0 + d_edge, c, seen_new);
        }
    }
    cout << dist.back().back() << endl;
    return 0;
}