#include <cstdio>
#include <vector>
#include <queue>
using namespace std;
const int nmax=2000, inf=1000000000;
typedef pair<int,int> ii;
vector<ii> g[nmax+3];
int prieteni[17];
int main()
{
    freopen("ubuntzei.in","r",stdin);
    freopen("ubuntzei.out","w",stdout);
    int n,m,k,lmin=0;
    scanf("%d%d%d",&n,&m,&k);
    int i,j;
    for(i=1;i<=k;i++)
    {
        scanf("%d",&prieteni[i]);
    }
    int x, y, z;
    ii aux;
    for(i=1;i<=m;i++)
    {
        scanf("%d%d%d",&x,&y,&z);
        aux.first=z;
        aux.second=y;
        g[x].push_back(aux);
        aux.second=x;
        g[y].push_back(aux);
    }
    vector<int> dist(n+1,inf);
    int start=1,distmin,prmin=k+1;
    priority_queue<ii, vector<ii>, greater<ii> > pq;
    ii asdf;
    for(i=1;i<=k;i++)
    {
        //aflam distanta pana la fiecare prieten
        dist[start]=0;
        pq.push(ii(0,start));
        while(!pq.empty())
        {
            asdf=pq.top();
            pq.pop();
            int d=asdf.first, u=asdf.second;
            if(d>dist[u])
                continue;
            for(j=0;j<(int)g[u].size();j++)
            {
                int duv=g[u][j].first, v=g[u][j].second;
                if(dist[u]+duv<dist[v])
                {
                    dist[v]=dist[u]+duv;
                    pq.push(ii(dist[v],v));
                }
            }
        }
        //vedem cel mai apropiat prieten si adunam distanta
        distmin=inf;
        for(j=1;j<=k;j++)
        {
            if(prieteni[j]==-1)
                continue;
            if(dist[prieteni[j]]<distmin)
            {
                distmin=dist[prieteni[j]];
                prmin=j;
            }
        }
        lmin+=distmin;
        //continuam cu acela
        start=prieteni[prmin];
        prieteni[prmin]=-1;
        for(j=0;j<=n;j++)
        {
            dist[j]=inf;
        }
    }
    dist[start]=0;
    pq.push(ii(0,start));
    while(!pq.empty())
    {
        asdf=pq.top();
        pq.pop();
        int d=asdf.first, u=asdf.second;
        if(d>dist[u])
            continue;
        for(j=0;j<(int)g[u].size();j++)
        {
            int duv=g[u][j].first, v=g[u][j].second;
            if(dist[u]+duv<dist[v])
            {
                dist[v]=dist[u]+duv;
                pq.push(ii(dist[v],v));
            }
        }
    }
    lmin+=dist[n];
    printf("%d",lmin);
    return 0;
}