#include <fstream>
#include <queue>
#define pi pair <int,int>
#define x first
#define mp make_pair
#define y second
#include <cstring>
using namespace std;
ifstream fin("ubuntzei.in");
ofstream fout("ubuntzei.out");
const int KMAX=17,NMAX=2005,inf=0x3f3f3f3f;
int dp[(1<<KMAX)][KMAX],u[KMAX],dist[KMAX][KMAX],dijkstra[NMAX];
vector<pi>H[NMAX];
struct cmp
{
    bool operator ()(const int &a,const int &b)
    {
        return dijkstra[a]>dijkstra[b];
    }
};
priority_queue<int,vector<int>,cmp>Q;
void drumminim(int start)
{
    memset(dijkstra,inf,sizeof(dijkstra));
    dijkstra[start]=0;
    Q.push(start);
    while(Q.size())
    {
        int nod=Q.top();
        Q.pop();
        for(vector<pi>::iterator it=H[nod].begin();it!=H[nod].end();it++)
        {
            if(dijkstra[it->x]>dijkstra[nod]+it->y)
            {
                dijkstra[it->x]=dijkstra[nod]+it->y;
                Q.push(it->x);
            }
        }
    }
}
int main()
{
    int n,m,i,j,k,a,b,c;
    fin>>n>>m>>k;
    for(i=1;i<=k;i++)
    {
        fin>>u[i];
    }
    for(i=1;i<=m;i++)
    {
        fin>>a>>b>>c;
        H[a].push_back(mp(b,c));
        H[b].push_back(mp(a,c));
    }
    u[0]=1;
    u[++k]=n;
    k++;
    for(i=0;i<k;i++)
    {
        drumminim(u[i]);
        for(j=0;j<k;j++)
        {
            dist[i][j]=dijkstra[u[j]];
        }
        dist[i][i]=0;
    }
    memset(dp,inf,sizeof(dp));
    int totK=(1<<k);
    dp[1][0]=0;
    for(int step=1;step<totK;step++)
    {
        for(i=0;i<k;i++)
        {
            if(step& (1<<i))
            {
                for(j=0;j<k;j++)
                {
                    if(step&(1<<j))
                    {
                        dp[step][i]=min(dp[step][i],dp[step^(1<<i)][j]+dist[j][i]);
                    }
                }
            }
        }
    }
    fout<<dp[totK-1][k-1];
}