#include <cstdio>
#include <algorithm>
#include <queue>
#include <functional>
using namespace std;
int n;
const int INF = 0x7fffffff;
struct Muchie {
  int v;
  int cost;
};
vector<Muchie>muchii[2005];
int distanta[2005];
int d[20][20];
bool viz[20][20][20];
int mat[20][20];
int ubuntzei[20];
struct Nod {
  int index;
  int dist;
  bool operator <(const Nod &other) const {
    return this->dist<other.dist;
  }
};
void dijkstra(int s) {
    for(int u=1; u<=n; u++)
        distanta[u]=INF;
    distanta[s]=0;
    priority_queue<Nod> q;
    q.push({s, 0});
    while(!q.empty()){
        int u=q.top().index;
        if(distanta[u]==q.top().dist){
            q.pop();
            for(Muchie e : muchii[u]){
                if(distanta[e.v]>distanta[u]+e.cost){
                    distanta[e.v]=distanta[u]+e.cost;
                    q.push({e.v, distanta[e.v]});
                }
            }
        } else
            q.pop();
    }
}
int main()
{   freopen("ubuntzei.in", "r",stdin);
    freopen("ubuntzei.out", "w",stdout);
    int m,k,i,x,y,z,j,kk,l,minn;
    scanf("%d%d%d", &n, &m, &k);
    for(i=1; i<=k; i++)
        scanf("%d", &ubuntzei[i]);
    ubuntzei[++k]=1;
    for(i=1; i<=m; i++){
        scanf("%d%d%d", &x, &y, &z);
        muchii[x].push_back({y,z});
        muchii[y].push_back({x,z});
    }
    for(i=1; i<=k; i++){
        dijkstra(ubuntzei[i]);
        for(j=1; j<=k; j++)
            mat[ubuntzei[i]][ubuntzei[j]]=mat[ubuntzei[j]][ubuntzei[i]]=distanta[j];
        mat[ubuntzei[i]][n]=distanta[n];
    }
    viz[1][1][k]=1;
    for(i=1; i<k; i++){
        d[2][i]+=mat[1][i];
        for(j=1; j<=k; j++)
            viz[2][i][j]=viz[1][1][j];
        viz[2][i][i]=1;
    }
    for(i=2; i<k; i++){
        for(j=1; j<=k; j++){
           if(d[i][j]){
                for(kk=1; kk<=k; kk++){
                    if(viz[i][j][kk]==0){
                        d[i+1][kk]=d[i][j]+mat[j][kk];
                        for(l=1; l<=k; l++)
                            viz[i+1][kk][l]=viz[i][j][l];
                        viz[i+1][kk][kk]=1;
                    }
                }
           }
        }
    }
    minn=INF;
    for(i=1; i<=k; i++)
        if(d[k][i]!=0)
            minn=min(minn, d[k][i]+mat[i][n]);
    printf("%d", minn);
    return 0;
}