#include <bits/stdc++.h>
#define edge pair<int, int>
#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")

using namespace std;

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

const int INF = 1e9;
const int LIM = 15;
const int DIM = 2005;
vector <edge> v[DIM];
int friends[LIM], minn[LIM][LIM], dp[(1<<(LIM-2))][LIM];

int n, m, k, x, y, c;

void set_friends(){
    for(int i=1; i<=k; i++)
        fin>>friends[i];
    friends[0]=1;
    friends[k+1]=n;
    k+=2;
}

set <edge> dij;
int dist[DIM];
void dijkstra(int start){
    int nod, nxt, cst;

    for(int i=1; i<=n; i++)
        dist[i] = INF;
    dist[start]=0;

    dij.insert({0, start});
    while(!dij.empty()){

        nod = dij.begin() -> second;
        dij.erase(dij.begin());

        for(int i=0; i<v[nod].size(); i++){
            nxt = v[nod][i].first;
            cst = v[nod][i].second;

            if(dist[nxt] > dist[nod] + cst){
                dij.erase({dist[nxt], nxt});
                dist[nxt] = dist[nod] + cst;
                dij.insert({dist[nxt], nxt});
            }
        }
    }
}


int main (){
    ios_base::sync_with_stdio(false); fin.tie(0); fout.tie(0);
    fin>>n>>m>>k;
    set_friends();

    while(m--){
        fin>>x>>y>>c;
        v[x].push_back({y, c});
        v[y].push_back({x, c});
    }

    for(int i=0; i<k; i++){
        dijkstra( friends[i] );

        for(int j=0; j<k; j++)
            if(i != j)
                minn[i][j] = minn[j][i] = dist[ friends[j] ];
    }

    for(int i=0; i < (1<<k); i++)
        for(int j=0; j < k; j++)
            dp[i][j] = INF;


    dp[0][0] = 0;
    for(int msk=0; msk < (1<<k); msk++)
        for(int lst=0; lst < k; lst++)
            if(msk & (1<<lst))
                for(int mid=0; mid < k; mid++)
                    dp[msk][lst] = min(dp[msk][lst], dp[msk^(1<<lst)][mid] + minn[mid][lst]);

    fout<<dp[(1<<k)-1][k-1];
    return 0;
}