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

using namespace std;

ofstream g("ubuntzei.out");

const int NMAX = 2005;
const int oo = (1 << 30);

int D[NMAX], N, M, K;
int Friends[NMAX];
bool InCoada[NMAX];

struct Compara{
    bool operator()(int x,int y){
        return D[x]>D[y];
    }
};

vector < pair < int, int > > G[NMAX];
priority_queue < int, vector < int > , Compara > Coada;

void Read(){
    ifstream f("ubuntzei.in");
    f >> N >> M >> K;
    for(int i = 1; i <= K;i++)
        f >> Friends[i];
    for(int i = 1; i <= M;i++){
        int x,y,c;
        f >> x >> y >> c;
        G[x].push_back(make_pair(y,c));
        G[y].push_back(make_pair(x,c));
    }

}

void Dijkstra(int Nod){
    for(int i = 1; i <= N;i++)
        D[i] = oo;
    D[Nod] = 0;
    Coada.push(Nod);
    InCoada[Nod] = true;
    while(!Coada.empty()){
        int nodCurent = Coada.top();
        Coada.pop();
        InCoada[Nod] = false;

        for(unsigned int i = 0; i < G[nodCurent].size();i++){
            int Vecin = G[nodCurent][i].first;
            int Cost = G[nodCurent][i].second;
            if(D[Vecin] > D[nodCurent]+ Cost){
                D[Vecin] = D[nodCurent] + Cost;
                if(!InCoada[Vecin]){
                    InCoada[Vecin] = true;
                    Coada.push(Vecin);
                }
            }
        }

    }

}
int main()
{
    Read();
    Dijkstra(1);
    g << D[N];
    return 0;
}