import java.io.*;
import java.util.*;

public class Main {
     public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int n = sc.nextInt();
        int m = sc.nextInt();
        int k = sc.nextInt();
        HashMap<Integer, Integer> specials = new HashMap<>();
        for (int i = 0; i < k; i++) {
            specials.put(sc.nextInt() - 1, i);
        }
        ArrayList<ArrayList<Path>> graph = new ArrayList<>();
        for (int i = 0; i < n; i++) {
            graph.add(new ArrayList<>());
        }
        for (int i = 0; i < m; i++) {
            int a = sc.nextInt() - 1;
            int b = sc.nextInt() - 1;
            int c = sc.nextInt();
            int d = 0;
            if (specials.containsKey(i)) {
                d = (1 << specials.get(i));
            }
            graph.get(a).add(new Path(b, c, d));
            graph.get(b).add(new Path(a, c, d));
        }
        PriorityQueue<Path> queue = new PriorityQueue<>();
        queue.add(new Path(0, 0, 0));
        int[][] costs = new int[1 << k][n];
        for (int[] arr : costs) {
            Arrays.fill(arr, Integer.MAX_VALUE);
        }
        while (queue.size() > 0) {
            Path p = queue.poll();
            if (costs[p.animal][p.idx] <= p.value) {
                continue;
            }
            costs[p.animal][p.idx] = p.value;
            for (Path x : graph.get(p.idx)) {
                queue.add(new Path(x.idx, x.value + p.value, x.animal | p.animal));
            }
        }
        System.out.println(costs[(1 << k) - 1][n - 1]);
    }
    
    static class Path implements Comparable<Path> {
        int idx;
        int value;
        int animal;
        
        public Path(int idx, int value, int animal) {
            this.idx = idx;
            this.value = value;
            this.animal = animal;
        }
        
        public int compareTo(Path another) {
            return value - another.value;
        }
    }
}
    
class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    StringBuilder sb = new StringBuilder();
    
    public Scanner() throws Exception {
        
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(next());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(next());
    }
    
    public double nextDouble() throws Exception {
        return Double.parseDouble(next());
    }
    
    public String next() throws Exception {
        while (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
    
}