#include <fstream>
#include <vector>
#include <queue>
#include <climits>
using namespace std;
ifstream fin("ubuntzei.in");
ofstream fout("ubuntzei.out");
const int nmax=2005;
int n,m,k;
int loc[nmax],d[nmax];
bool inCoada[nmax];
const int inf=INT_MAX;
vector <pair<int,int>> muchii[nmax];
struct cmp
{
    bool operator() (int x,int y)
    {
        return d[x]>d[y];
    }
};
priority_queue <int,vector<int>,cmp> q;
void dijkstra(int start)
{
    for (int i=1;i<=n;i++)
    {
        d[i]=inf;
    }
    d[start]=0;
    q.push(start);
    inCoada[start]=true;
    while (!q.empty())
    {
        int nod=q.top();
        q.pop();
        inCoada[nod]=false;
        for (int i=0;i<muchii[nod].size();i++)
        {
            int vecin=muchii[nod][i].first;
            int cost=muchii[nod][i].second;
            if (d[nod]+cost<d[vecin])
            {
                d[vecin]=d[nod]+cost;
                if (inCoada[vecin]==false)
                {
                    q.push(vecin);
                    inCoada[vecin]=true;
                }
            }
        }
    }
}
int main()
{
    fin >> n >> m;
    fin >> k;
    for (int i=1;i<=k;i++)
    {
        fin >> loc[i];
    }
    for (int i=1;i<=m;i++)
    {
        int x,y,c;
        fin >> x >> y >> c;
        muchii[x].push_back(make_pair(y,c));
        muchii[y].push_back(make_pair(x,c));
    }
    dijkstra(1);
    fout << d[n];
}