import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.PriorityQueue;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;
import java.util.stream.Stream;
import java.util.StringTokenizer;
import java.io.Writer;
import java.io.OutputStreamWriter;
import java.io.BufferedReader;
import java.util.Comparator;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 *
 * @author lewin
 */
public class travel_log_lewin {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader2 in = new InputReader2(inputStream);
        OutputWriter out = new OutputWriter(outputStream);
        TravelLog solver = new TravelLog();
        solver.solve(1, in, out);
        out.close();
    }

    static class TravelLog {
        List<TravelLog.Edge>[] graph;

        public void solve(int testNumber, InputReader2 in, OutputWriter out) {
            int n = in.nextInt(), m = in.nextInt(), d = in.nextInt();
            graph = LUtils.genArrayList(n);
            for (int i = 0; i < m; i++) {
                int a = in.nextInt() - 1, b = in.nextInt() - 1;
                long c = in.nextLong();
                graph[a].add(new TravelLog.Edge(b, c));
            }
            long[] ds = in.readLongArray(d);
            AUtils.sort(ds);

            PriorityQueue<TravelLog.Edge> pq = new PriorityQueue<>(Comparator.comparingLong(x -> x.weight));
            long[] dist = new long[n];
            Arrays.fill(dist, 1L << 60);
            pq.add(new TravelLog.Edge(0, dist[0] = 0));
            int[] order = new int[n];
            int oid = 0;
            while (pq.size() > 0) {
                TravelLog.Edge e = pq.poll();
                if (e.weight != dist[e.to]) continue;
                order[oid++] = e.to;
                for (TravelLog.Edge nxt : graph[e.to]) {
                    if (nxt.weight + e.weight < dist[nxt.to]) {
                        pq.add(new TravelLog.Edge(nxt.to, dist[nxt.to] = nxt.weight + e.weight));
                    }
                }
            }

            if (ds[d - 1] > dist[n - 1]) {
                out.println(0);
                return;
            }
            int[] nways = new int[n];
            int[] prev = new int[n];
            Arrays.fill(prev, -1);
            nways[0] = 1;
            int ptr = 0;
            for (int node : order) {
                if (nways[node] == 0) continue;
                if (ptr < d && dist[node] >= ds[ptr]) ptr++;
                nways[node] = Math.min(nways[node], 2);
                for (TravelLog.Edge nxt : graph[node]) {
                    if (nxt.weight + dist[node] == dist[nxt.to]) {
                        if (ptr >= d || dist[nxt.to] <= ds[ptr]) {
                            nways[nxt.to] += nways[node];
                            prev[nxt.to] = node;
                        }
                    }
                }
            }
            if (nways[n - 1] == 0) {
                out.println(0);
                return;
            }
            if (nways[n - 1] > 1) {
                out.println(1);
                return;
            }
            List<Integer> ret = new ArrayList<>();
            int cur = n - 1;
            while (cur != -1) {
                ret.add(cur);
                cur = prev[cur];
            }
            out.println(ret.size());
            for (int i = ret.size() - 1; i >= 0; i--) {
                out.println(ret.get(i) + 1);
            }
            out.println();
        }

        static class Edge {
            public long weight;
            public int to;

            public Edge(int to, long weight) {
                this.weight = weight;
                this.to = to;
            }

        }

    }

    static class OutputWriter {
        private final PrintWriter writer;

        public OutputWriter(OutputStream outputStream) {
            writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
        }

        public OutputWriter(Writer writer) {
            this.writer = new PrintWriter(writer);
        }

        public void print(Object... objects) {
            for (int i = 0; i < objects.length; i++) {
                if (i != 0) {
                    writer.print(' ');
                }
                writer.print(objects[i]);
            }
        }

        public void println() {
            writer.println();
        }

        public void println(Object... objects) {
            print(objects);
            writer.println();
        }

        public void close() {
            writer.close();
        }

        public void print(int i) {
            writer.print(i);
        }

        public void println(int i) {
            writer.println(i);
        }

    }

    static class InputReader2 {
        private BufferedReader in;
        private StringTokenizer st;

        public InputReader2(InputStream stream) {
            in = new BufferedReader(new InputStreamReader(stream));
            st = null;
        }

        public long[] readLongArray(int tokens) {
            long[] ret = new long[tokens];
            for (int i = 0; i < tokens; i++) {
                ret[i] = nextLong();
            }
            return ret;
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }

        public long nextLong() {
            return Long.parseLong(next());
        }

        public String next() {
            while (st == null || !st.hasMoreTokens()) {
                try {
                    st = new StringTokenizer(in.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

    }

    static class LUtils {
        public static <E> List<E>[] genArrayList(int size) {
            return Stream.generate(ArrayList::new).limit(size).toArray(List[]::new);
        }

    }

    static class AUtils {
        public static void sort(long[] arr) {
            for (int i = 1; i < arr.length; i++) {
                int j = (int) (Math.random() * (i + 1));
                if (i != j) {
                    long t = arr[i];
                    arr[i] = arr[j];
                    arr[j] = t;
                }
            }
            Arrays.sort(arr);
        }

    }
}