#include <bits/stdc++.h>
using namespace std;
int main(){
  int N, M, K;
  cin >> N >> M >> K;
  vector<int> R(K);
  for (int i = 0; i < K; i++){
    cin >> R[i];
    R[i]--;
  }
  vector<int> A(M), B(M), C(M);
  for (int i = 0; i < M; i++){
    cin >> A[i] >> B[i] >> C[i];
    A[i]--;
    B[i]--;
  }
  vector<vector<pair<int, int>>> E(N);
  for (int i = 0; i < M; i++){
    E[A[i]].push_back(make_pair(C[i], B[i]));
    E[B[i]].push_back(make_pair(C[i], A[i]));
  }
  vector<int> id;
  id.push_back(0);
  id.push_back(N - 1);
  for (int i = 0; i < K; i++){
    id.push_back(A[R[i]]);
    id.push_back(B[R[i]]);
  }
  int V = id.size();
  vector<vector<int>> d(V, vector<int>(V));
  for (int i = 0; i < V; i++){
    vector<int> d2(N, -1);
    priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> pq;
    pq.push(make_pair(0, id[i]));
    while (!pq.empty()){
      int c = pq.top().first;
      int v = pq.top().second;
      pq.pop();
      if (d2[v] == -1){
        d2[v] = c;
        for (auto P : E[v]){
          int w = P.second;
          if (d2[w] == -1){
            pq.push(make_pair(c + P.first, w));
          }
        }
      }
    }
    for (int j = 0; j < V; j++){
      d[i][j] = d2[id[j]];
    }
  }
  vector<vector<int>> T(V, vector<int>(V, -1));
  for (int i = 0; i < K; i++){
    d[i * 2 + 2][i * 2 + 3] = C[R[i]];
    d[i * 2 + 3][i * 2 + 2] = C[R[i]];
    T[i * 2 + 2][i * 2 + 3] = i;
    T[i * 2 + 3][i * 2 + 2] = i;
  }
  vector<vector<int>> d2(1 << K, vector<int>(V, -1));
  priority_queue<tuple<int, int, int>, vector<tuple<int, int, int>>, greater<tuple<int, int, int>>> pq;
  pq.push(make_tuple(0, 0, 0));
  while (!pq.empty()){
    int c = get<0>(pq.top());
    int s = get<1>(pq.top());
    int v = get<2>(pq.top());
    pq.pop();
    if (d2[s][v] == -1){
      d2[s][v] = c;
      for (int i = 0; i < V; i++){
        int s2 = s;
        if (T[v][i] != -1){
          s2 |= 1 << T[v][i];
        }
        if (d2[s2][i] == -1){
          pq.push(make_tuple(c + d[v][i], s2, i));
        }
      }
    }
  }
  cout << d2[(1 << K) - 1][1] << endl;
}