#include <string.h>
#include <fstream>
#include <vector>
#include <queue>
#include <algorithm>
#define NMax 2002
#define INF 1<<30
#define minim(a,b)(a>b?b:a)
using namespace std;
ifstream fin("ubuntzei.in");
ofstream fout("ubuntzei.out");
std::vector< std::pair<int,int> > G[NMax];
std::vector<int> A;
std::queue< std::pair<int,int> > coada;
int n,m,k,x,y,cost,d[NMax],CF[(1<<19)][20],Maxim,AD[20][20];
void dijkstra(int x0)
{
    fill(d+1,d+n+1,INF);
    d[x0] = 0;
    coada.push(std::make_pair(x0,0));
    while(!coada.empty())
    {
        int nod = (coada.front()).first;
        int val = (coada.front()).second;
        coada.pop();
        for(int i=0;i<G[nod].size();++i)
        {
            if(d[G[nod][i].first] > val + G[nod][i].second)
            {
                d[G[nod][i].first] = val + G[nod][i].second;
                coada.push(std::make_pair(G[nod][i].first,d[G[nod][i].first]));
            }
        }
    }
}

int main()
{
    Maxim = INF;
    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( std::make_pair(y,cost) );
        G[y].push_back( std::make_pair(x,cost) );
    }
    if(k==0)
    {
        dijkstra(1);
        fout<<d[n];
    }
    else
    {
        A.push_back(1);
        A.push_back(n);
        sort(A.begin(),A.end());
        for(int i=0;i<A.size();++i)
        {
            dijkstra(A[i]);
            for(int j=0;j<A.size();++j)
            {
                AD[i][j] = d[A[j]];
            }
            AD[i][i] = 0;
        }
        //memset(CF,INF,sizeof(CF));
        for(int i=0;i<(1<<(A.size()+1));++i)
        {
            fill(CF[i],CF[i]+18,INF);
        }
        CF[1][0] = 0;
        for(int j=0;j<A.size();++j)
        {
            for(int p=0;p<A.size();++p)
            {
                for(int i=1;i<(1<<A.size());++i)
                {
                    if( i&(1<<j) && i&(1<<p) )
                    {
                        CF[i][j] = minim(CF[i][j],CF[i^(1<<j)][p]+AD[p][j]);
                    }
                }
            }
        }
        /*for(int i=1;i<(1<<A.size());++i)
        {
            for(int j=0;j<A.size();++j)
            {
                if(i&(1<<j))
                {
                    for(int p=0;p<A.size();++p)
                    {
                        if(i&(1<<p))
                        {
                            CF[i][j] = minim(CF[i][j],CF[i^(1<<j)][p]+AD[p][j]);
                        }
                    }
                }
            }
        }*/
        fout<<CF[(1<<A.size())-1][A.size()-1];
    }
    return 0;
}