#include <fstream>
#include <vector>
#include <queue>
#include <algorithm>
#define NMax 2002
#define INF 1<<30
using namespace std;
ifstream fin("ubuntzei.in");
ofstream fout("ubuntzei.out");
std::vector<int> G[NMax],C[NMax],A;
std::queue< std::pair<int,int> > coada;
int n,m,k,x,y,cost,d[NMax];
void dijkstra(int x0)
{
    fill(d+1,d+n+1,INF);
    d[0] = 0;
    coada.push(std::make_pair(0,x0));
    while(coada.empty()==0)
    {
        int val = (coada.front()).first;
        int nod = (coada.front()).second;
        coada.pop();
        for(int i=0;i<G[nod].size();++i)
        {
            if(d[G[nod][i]] > val + C[nod][i])
            {
                d[G[nod][i]] = val + C[nod][i];
                coada.push(std::make_pair(d[G[nod][i]],G[nod][i]));
            }
        }
    }
    fout<<d[n];
}
int main()
{
    fin>>n>>m>>k;
    for(int i=1;i<=k;++i)
    {
        fin>>x;
        A.push_back(x);
    }
    for(int i=1;i<=m;++i)
    {
        fin>>x>>y>>cost;
        G[x].push_back(y);
        G[y].push_back(x);
        C[x].push_back(cost);
        C[y].push_back(cost);
    }
    dijkstra(1);
    return 0;
}