#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[20];
int dist[2005];
int drum[20][20];
int dp[1<<17][17];

void dijkstra(int src) {
    for(int i = 1; i <= n; i++) dist[i] = -1;
    priority_queue<pair<int, int> > q;
    q.push({0, src});

    while(!q.empty()) {
        int d = -q.top().first;
        int curr = q.top().second;
        q.pop();

        if(dist[curr] != -1) continue;
        dist[curr] = d;

        for(int i = 0; i < g[curr].size(); i++)
            q.push({-d-g[curr][i].second, g[curr][i].first});
    }
}


void citire() {
    fin >> n >> m >> k;
    for(int i = 1; i <= k; i++)
        fin >> prieteni[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() {
    if(k == 0) {
        dijkstra(1);
        fout << dist[n];
        return;
    }

    prieteni[0] = 1, prieteni[++k] = n;

    for(int i = 0; i <= k; i++) {
        dijkstra(prieteni[i]);
        for(int j = 0; j <= k; j++)
            drum[i][j] = dist[prieteni[j]];
    }
    k--;

    for(int i = 0; i <= 1<<k; i++)
        for(int j = 0; j <= k; j++)
            dp[i][j] = 1000000000;
    dp[0][0] = 0;
    for(int i = 0; i < 1<<k; i++)
        for(int j = 0; j < k; j++)
            if(i&(1<<j))
                for(int l = 0; l <= k; l++)
                    dp[i][j+1] = min(dp[i][j+1], dp[i-(1<<j)][l]+drum[l][j+1]);

    int best = 1000000000;
    for(int i = 1; i <= k; i++)
        best = min(best, dp[(1<<k)-1][i]+drum[i][k+1]);
    fout << best;
}

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