#include <iostream>
#include <fstream>
#include <queue>
#include <vector>
#include <cmath>
#define N 2005
#define pinf 1000000100
using namespace std;

int D[N][1025];

struct Elem
{
  int  dist;
  unsigned short int nod, val_mult;

};
class Compar
{
 public:
 bool operator()( Elem x, Elem y)
 {
    return x.dist>y.dist;
 }
};

priority_queue<  Elem, vector< Elem >, Compar > coada;

int n,m,k, loc[16];

vector <vector< pair< int, int> > >L(N);

ifstream f("ubuntzei.in");
ofstream g("ubuntzei.out");

int apartine(int nod)
{
    for(int i=1;i<=16;i++)
      if(loc[i]==nod) return i;
    return 0;
}
void dijkstra(int r)
{
    int i,poz,c,j,v,z;
    Elem x;

    for(i=1;i<=n;i++)
     for(j=1;j<=3300;j++)
       D[i][j]=pinf;

    x.nod=r; x.dist=0;  x.val_mult=0; //init_mult(x.mult);
    coada.push(x);D[r][0]=0;

    while(!coada.empty())
    {
        x=coada.top();
        poz=x.nod; c=x.dist; v=x.val_mult;
        coada.pop();

        if(D[poz][v]==c)
          for(i=0;i<L[poz].size();i++)
          {
              int nod=L[poz][i].first;
              int z=apartine(nod), vv=v;
              if(z )
              { int b=pow(2,z-1);
                if( !(v&b)) //nodul e in mult k
                   vv=v+b;
              }
              if(D[nod][vv]>D[poz][v]+L[poz][i].second )
              {
                D[nod][vv]=D[poz][v]+L[poz][i].second;
                x.nod=nod;x.dist=D[nod][vv]; x.val_mult=vv;
                coada.push(x);

              }
          }
    }
}

int main()
{
   int x,y,c,i;
   f>>n>>m;
   f>>k;
   for(i=1;i<=k;i++)
     f>>loc[i];
   for(i=1;i<=m;i++)
   {
      f>>x>>y>>c;
      L[x].push_back(make_pair(y,c));
      L[y].push_back(make_pair(x,c));
   }

   dijkstra(1);
   int val=0,put=1;
   for(i=1;i<=k;i++)
   {
      val+=put;put*=2;
   }

   g<<D[n][val]<<" ";


   f.close();
   g.close();
   return 0;
}