#include <bits/stdc++.h>

#define INF 2140000000
#define MOD 1000000007
#define MaxN 2005
#define Mask 1<<15

using namespace std;

FILE *IN=fopen("ubuntzei.in","r"),*OUT=fopen("ubuntzei.out","w");

int N,M,K,X,Y,Z,d[MaxN][Mask],spec[MaxN];
vector<pair<short,int> > Graph[MaxN];
queue<pair<short,int> >Q;
void BFS(short node,int mask)
{
    Q.push({node,mask});
    while(!Q.empty())
    {
        node=Q.front().first;
        mask=Q.front().second;
        Q.pop();
        for(int i=0;i<Graph[node].size();i++)
        {
            if(spec[Graph[node][i].first]!=-1&&!(mask&(1<<spec[Graph[node][i].first]))&&(d[Graph[node][i].first][mask+(1<<spec[Graph[node][i].first])]==0||d[Graph[node][i].first][mask+(1<<spec[Graph[node][i].first])]>Graph[node][i].second+d[node][mask]))
            {
                d[Graph[node][i].first][mask+(1<<spec[Graph[node][i].first])]=Graph[node][i].second+d[node][mask];
                Q.push({Graph[node][i].first,mask+(1<<spec[Graph[node][i].first])});
            }
            else if(d[Graph[node][i].first][mask]==0||d[Graph[node][i].first][mask]>Graph[node][i].second+d[node][mask])
            {
                d[Graph[node][i].first][mask]=Graph[node][i].second+d[node][mask];
                Q.push({Graph[node][i].first,mask});
            }
        }
    }
}
int main()
{
    fscanf(IN,"%d %d %d",&N,&M,&K);

    for(int i=1;i<=N;i++)
        spec[i]=-1;

    for(int i=0;i<K;i++)
    {
        fscanf(IN,"%d",&X);
        spec[X]=i;
    }
    for(int i=1;i<=M;i++)
    {
        fscanf(IN,"%d %d %d",&X,&Y,&Z);
        Graph[X].push_back({Y,Z});
        Graph[Y].push_back({X,Z});
    }

    BFS(1,0);

    fprintf(OUT,"%d",d[N][(1<<K)-1]);

    return 0;
}