#include <fstream>
#include <queue>
#include <vector>

using namespace std;

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

int ubuntzei[16];
int distmin[16][2001];
struct HeapNode
{
    int nod;
    long long dist_tot;
    bool operator <(const HeapNode &other) const
    {
        return dist_tot>other.dist_tot;
    }
};
vector <HeapNode> matad[2001];

priority_queue <HeapNode> pq;

void dijkstra(int start, int pozub)
{
    HeapNode prim;
    prim.nod=start;
    prim.dist_tot=0;
    pq.push(prim);
    distmin[pozub][start]=0;
    while(!pq.empty())
    {
        HeapNode top=pq.top();
        pq.pop();
        if(distmin[pozub][top.nod]<top.dist_tot)
            continue;
        int p=matad[top.nod].size();
        for(int i=0; i<p; i++)
        {
            int destinatie=matad[top.nod][i].nod;
            int costdestinatie=matad[top.nod][i].dist_tot;

            if(top.dist_tot+costdestinatie<distmin[pozub][destinatie])
            {
                distmin[pozub][destinatie]=top.dist_tot+costdestinatie;
                HeapNode vecin;
                vecin.nod=destinatie;
                vecin.dist_tot=distmin[pozub][destinatie];
                pq.push(vecin);
            }
        }
    }
}

int main()
{
    int n,m;
    cin>>n>>m;
    int k;
    cin>>k;
    for(int i=1; i<=k; i++)
        cin>>ubuntzei[i];

    for(int i=1; i<=m; i++)
    {
        int x,y,c;
        cin>>x>>y>>c;
        HeapNode a;
        a.dist_tot=c;
        a.nod=y;
        matad[x].push_back(a);
        a.nod=x;
        matad[y].push_back(a);
    }

    for(int i=0; i<=k; i++)
    {
        for(int j=1; j<=n; j++)
            distmin[i][j]=1e9;
    }

    if(k==0)
    {
        dijkstra(1,0);
        distmin[0][1]=0;
        /*for(int i=1;i<=n;i++)
            cout<<distmin[0][i]<<'\n';*/
        cout<<distmin[0][n]<<'\n';
    }
    /*else
    {

        for(int i=1; i<=k; i++)
            dijkstra(ubuntzei[i], i);

        for(int i=)
    }*/

    return 0;
}