#include<bits/stdc++.h>
using namespace std;

bool chmin(int &x,int y) {
    if(x > y) {
        x = y;
        return true;
    }
    return false;
}

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<vector<array<int,3>>>road(N);
    vector<pair<int,int>>R2;
    for(int i = 0; i < M; i++) {
        int A,B,C;
        cin >> A >> B >> C;
        A--;
        B--;
        int id = -1;
        for(int j = 0; j < K; j++) {
            if(R[j] == i) {
                id = j;
            }
        }
        if(id != -1) {
            R2.push_back({A,id});
            R2.push_back({B,id});
        }
        road[A].push_back({B,C,id});
        road[B].push_back({A,C,id});
    }
    R2.push_back({0,-1});
    R2.push_back({N-1,-1});
    vector<vector<int>>dist(2*K+2,vector<int>(N,1001001001));
    for(int t = 0; t < 2*K+2; t++) {
        priority_queue<array<int,3>,vector<array<int,3>>,greater<array<int,3>>>que;
        dist[t][R2[t].first] = 0;
        que.push({0,t,R2[t].first});
        while (!que.empty()) {
            auto x = que.top();
            que.pop();
            if(dist[x[1]][x[2]] != x[0]) {
                continue;
            }
            for(auto i:road[x[2]]) {
                int to1 = t;
                int to2 = i[0];
                if(chmin(dist[to1][to2],i[1]+x[0])) {
                    que.push({i[1]+x[0],to1,to2});
                }
            }
        }
    }
    vector<vector<array<int,3>>>road2(2*K+2);
    for(int i = 0; i < 2*K+2; i++) {
        for(int j = 0; j < 2*K+2; j++) {
            road2[i].push_back({j,dist[i][R2[j].first],-1});
        }
    }
    for(int i = 0; i < N; i++) {
        for(int j = 0; j < road[i].size(); j++) {
            if(road[i][j][2] != -1) {
                int id1 = 0,id2 = 0;
                for(int k = 0; k < 2*K+2; k++) {
                    if(i == R2[k].first) {
                        id1 = k;
                    }
                    if(road[i][j][0] == R2[k].first) {
                        id2 = k;
                    }
                }
                road2[id1].push_back({id2,road[i][j][1],road[i][j][2]});
            }
        }
    }
    vector<vector<int>>dist2(2*K+2,vector<int>(1 << K,1001001001));
    priority_queue<array<int,3>,vector<array<int,3>>,greater<array<int,3>>>que;
    dist2[2*K][0] = 0;
    que.push({0,2*K,0});
    while (!que.empty()) {
        auto x = que.top();
        que.pop();
        if(dist2[x[1]][x[2]] != x[0]) {
            continue;
        }
        for(auto i:road2[x[1]]) {
            int to1 = i[0];
            int to2 = x[2];
            if(i[2] != -1) {
                to2 |= (1 << i[2]);
            }
            if(chmin(dist2[to1][to2],i[1]+x[0])) {
                que.push({i[1]+x[0],to1,to2});
            }
        }
    }
    cout << dist2[2*K+1][(1 << K)-1] << endl;
}