#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#include <cstring>

#define inf 0x3f3f3f3f
#define GMAX 2010
using namespace std;
ifstream f ("ubuntzei.in");
ofstream g ("ubuntzei.out");

struct point
{
    int nod;
    int cost;
};
bool operator<(point a,point b)
{
    return a.cost > b.cost;
}
bool friends[GMAX];
vector<pair <int,int> > G[GMAX];
priority_queue <point> pq;

void clearPQ(priority_queue<point> &q)
{
    priority_queue <point> empti;
    swap(q,empti);
}

int dist[GMAX];
int costuri[GMAX];

int main()
{
    int n,m,k;
    f>>n>>m>>k;
    for(int i=1;i<=k;i++)
    {
        int p;
        f>>p;
        friends[p] = true;
    }

    for(int i=1;i<=m;i++)
    {
        int x,y,z;
        f>>x>>y>>z;
        G[x].push_back(make_pair(y,z));
        G[y].push_back(make_pair(x,z));
    }
    memset(dist, 0x3f, sizeof(dist));

    pq.push({1,0});
    int I = 0;
    while(!pq.empty())
    {

        int nod = pq.top().nod;
        int cost = pq.top().cost;
        pq.pop();

        if(dist[nod]!= inf)
            continue;
        if(friends[nod])
        {
            I++;
            costuri[I] = cost;
            clearPQ(pq);
            pq.push({nod,0});
            memset(dist, 0x3f, sizeof(dist));
            friends[nod] = false;
            continue;
        }
        dist[nod] = cost;

        for(int i=0;i<G[nod].size();i++)
        {
            pq.push({G[nod][i].first,G[nod][i].second + cost});
        }
    }
    int s=0;
    for(int i=1;i<=I;i++)
        s+=costuri[i];
    g<<s+dist[n];


    return 0;
}