#include <fstream>
#include <vector>
#include <queue>
#define INF 1<<30

using namespace std;

ifstream fin("ubuntzei.in");
ofstream fout("ubuntzei.out");

queue<int> cd;
vector<pair<int,int> > v[50001];
int n,m,i,j,k,l,p,x,y,c,sz;
int drum[50001];
int Cost[20][20];
int dinamica[1<<17][20];
int prieten[20];
int pCurent,indCurent,nod;
pair<int,int> a;

int main()
{
    fin>>n>>m>>k;
    for (i=1;i<=k;i++)
        fin>>prieten[i];
    prieten[0] = 1;
    prieten[k+1] = n;
    for (i=1;i<=m;i++)
    {
        fin>>x>>y>>c;
        v[x].push_back(make_pair(y,c));
        v[y].push_back(make_pair(x,c));
    }
    k+=2;
    for (i=0;i<k;i++)
    {
        pCurent = prieten[i];
        indCurent = i;
        cd.push(prieten[i]);
        for (j=1;j<=n;j++)
            drum[j] = INF;
        drum[pCurent] = 0;
        while (!cd.empty())
        {
            nod = cd.front();
            cd.pop();
            for (vector<pair<int,int> >::iterator it = v[nod].begin(); it != v[nod].end(); ++ it)
            {
                sz = sizeof(cd);
                a = *it;
                if (drum[a.first] > drum[nod] + a.second)
                {
                    drum[a.first] = drum[nod] + a.second;
                    cd.push(a.first);
                }
            }
        }
        for (j=0;j<k;j++)
        {
            Cost[indCurent][j] = drum[prieten[j]];
            Cost[j][indCurent] = drum[prieten[j]];
        }
    }
    for (i=0;i<=(1<<k);i++)
        for (j=0;j<k;j++)
            dinamica[i][j] = INF;
    dinamica[1][0] = 0;
    for (i=0;i<=(1<<k);i++)
        for (j=0;j<k;j++)
            if (i&(1<<j))
                for (p=0;p<k;p++)
                    if (i&(1<<p) && p != j)
                        dinamica[i][j] = min(dinamica[i][j], dinamica[i^(1<<j)][p] + Cost[p][j]);
    fout<<dinamica[(1<<k)-1][k-1];
    return 0;
}