#include <iostream>
#include <fstream>
#include <queue>
#include <vector>
#include <cmath>
#include <cstdlib>
#define N 2005
#define pinf 1000000100

using namespace std;



int D[N][4100];
unsigned short int puteri[16]={0,1,2,4,8,16,32,64,128,256, 512,1024,2048,4096,0,0 };

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<=k;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<4100;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=puteri[z];
             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;
   if(k>12) exit(0);
   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;

}