#include <iostream>
#include <vector>
#include <algorithm>
#include <queue>
using namespace std;
using i64 = long long;
using u64 = unsigned long long;
using i32 = int;
using u32 = unsigned int;
#define rep(i,n) for(int i=0; i<(n); i++)

template<class E>
using nega_queue = priority_queue<E,vector<E>,greater<E>>;

struct Edge{ int u,v,c; };
struct AdjEdge{ int to; i64 d; };

int N,M;
vector<Edge> J;
vector<vector<AdjEdge>> E;
int K;
vector<int> R;


vector<i64> dist(int s){
    nega_queue<pair<i64,int>> Q;
    vector<i64> D(E.size(), 1001001001001001001);
    Q.push({ 0,s });
    D[s] = 0;
    while(Q.size()){
        auto [d,p] = Q.top(); Q.pop();
        if(D[p] != d) continue;
        for(auto [to,dd] : E[p]){
            if(D[to] <= d+dd) continue;
            D[to] = d+dd;
            Q.push({ D[to],to });
        }
    }
    return D;
}


int main() {
    cin >> N >> M >> K;
    E.resize(N);
    J.resize(M);
    R.resize(K);
    rep(i,K){ cin >> R[i]; R[i]--; }
    rep(i,M){
        int u,v,c; cin >> u >> v >> c; u--; v--;
        J[i] = {u,v,c};
        E[u].push_back({v,c});
        E[v].push_back({u,c});
    }
    
    vector<int> Rp(K*2);
    rep(i,K) Rp[i*2] = J[R[i]].u;
    rep(i,K) Rp[i*2+1] = J[R[i]].v;

    vector<vector<AdjEdge>> G2(K*2 * (1<<K) + 2);
    const int ZG2 = K*2 * (1<<K);
    rep(i,K*2){
        auto D = dist(Rp[i]);
        rep(j,K*2){
            i64 d = D[Rp[j]];
            rep(b,1<<K) G2[(i<<K)+b].push_back({ (j<<K)+b, d });
        }
    }
    
    rep(k,K*2) rep(b,1<<K) G2[(k<<K)+b].push_back({ ((k^1)<<K)+(b|(1<<(k/2))), J[R[k/2]].c });

    {
        auto D = dist(0);
        rep(j,K*2) G2[ZG2].push_back({ j<<K, D[Rp[j]] });
    }
    {
        auto D = dist(N-1);
        rep(j,K*2) G2[((j+1)<<K)-1].push_back({ ZG2+1, D[Rp[j]] });
    }

    E = G2;
    auto D = dist(ZG2);
    i64 ans = D[ZG2+1];
    cout << ans << endl;

    return 0;
}



struct ios_do_not_sync{
    ios_do_not_sync(){
        std::ios::sync_with_stdio(false);
        std::cin.tie(nullptr);
    }
} ios_do_not_sync_instance;