#include <queue>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <cstring>

#define pb push_back
#define mp make_pair
#define cost first
#define vecin second

#define NMAX 2005
#define INF 0x3f3f3f3f

using namespace std;

int n,m,k,L;
int v[NMAX],d[NMAX],need[NMAX];
vector<pair<int,int> > g[NMAX];

void read()
{
    int i,a,b,c;
    scanf("%d%d%d",&n,&m,&k);
    for(i=0;i<k;++i)
    {
        scanf("%d",&a);
        need[a]=1;
    }
    for(i=0;i<m;++i)
    {
        scanf("%d%d%d",&a,&b,&c);
        g[a].pb(mp(c,b));
        g[b].pb(mp(c,a));
    }
}

void dijkstra(int k)
{
    priority_queue<pair<int,int> > h;
    h.push(mp(0,k));
    d[k]=0;
    while(!h.empty())
    {
        k=h.top().vecin;
        h.pop();
        for(vector<pair<int,int> >::iterator it=g[k].begin();it!=g[k].end();++it)
        {
            if(d[it->vecin]>d[k]+it->cost)
            {
                d[it->vecin]=d[k]+it->cost;
                h.push(mp(-d[it->vecin],it->vecin));
            }
        }
    }
}

void solve()
{
    need[n]=1;
    memset(d,INF,sizeof(d));
    dijkstra(1);
    for(int i=0;i<=k;++i)
    {
        int min=INF,jmin;
        for(int j=1;j<=n;++j)
            if(d[j]<min&&need[j])
            {
                min=d[j];
                jmin=j;
            }
        L+=d[jmin];
        need[jmin]=0;
        memset(d,INF,sizeof(d));
        dijkstra(jmin);
    }
}

int main()
{
    freopen("ubuntzei.in","r",stdin);
    freopen("ubuntzei.out","w",stdout);
    read();
    solve();
    printf("%d\n",L);
    return 0;
}