Problem: Petya and Vasya arranged a game. The game runs by the following rules. Players have a directed graph consisting of n vertices and m edges. One of the vertices contains a chip. Initially the chip is located at vertex s. Players take turns moving the chip along some edge of the graph. Petya goes first. Player who can't move the chip loses. If the game lasts for 106 turns the draw is announced.

Vasya was performing big laboratory work in "Spelling and parts of speech" at night before the game, so he fell asleep at the very beginning of the game. Petya decided to take the advantage of this situation and make both Petya's and Vasya's moves.

Your task is to help Petya find out if he can win the game or at least draw a tie.

Input

The first line of input contain two integers n and m — the number of vertices and the number of edges in the graph (2 ≤ n ≤ 105, 0 ≤ m ≤ 2·105).

The next n lines contain the information about edges of the graph. i-th line (1 ≤ i ≤ n) contains nonnegative integer ci — number of vertices such that there is an edge from i to these vertices and ci distinct integers ai, j — indices of these vertices (1 ≤ ai, j ≤ n, ai, j ≠ i).

It is guaranteed that the total sum of ci equals to m.

The next line contains index of vertex s — the initial position of the chip (1 ≤ s ≤ n).

Output

If Petya can win print «Win» in the first line. In the next line print numbers v1, v2, ..., vk (1 ≤ k ≤ 106) — the sequence of vertices Petya should visit for the winning. Vertex v1 should coincide with s. For i = 1... k - 1 there should be an edge from vi to vi + 1 in the graph. There must be no possible move from vertex vk. The sequence should be such that Petya wins the game.

If Petya can't win but can draw a tie, print «Draw» in the only line. Otherwise print «Lose».

Examples

Input

5 6
2 2 3
2 4 5
1 4
1 5
0
1


Output

Win
1 2 4 5 


Input

3 2
1 3
1 1
0
2


Output

Lose


Input

2 2
1 2
1 1
1


Output

Draw

Note

In the first example the graph is the following:

<image>

Initially the chip is located at vertex 1. In the first move Petya moves the chip to vertex 2, after that he moves it to vertex 4 for Vasya. After that he moves to vertex 5. Now it is Vasya's turn and there is no possible move, so Petya wins.

In the second example the graph is the following:

<image>

Initially the chip is located at vertex 2. The only possible Petya's move is to go to vertex 1. After that he has to go to 3 for Vasya. Now it's Petya's turn but he has no possible move, so Petya loses.

In the third example the graph is the following:

<image>

Petya can't win, but he can move along the cycle, so the players will draw a tie.

Solution (in JAVA):

Solution:
import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Arrays;
import java.util.InputMismatchException;
import java.io.OutputStreamWriter;
import java.util.NoSuchElementException;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.Iterator;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.Writer;
import java.io.InputStream;

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

    static class TaskD {
        public void solve(int testNumber, InputReader in, OutputWriter out) {
            Thread t = new Thread(null, new Run(in, out), "name", 1 << 28);
            t.start();
            try {
                t.join();
            } catch (InterruptedException e) {

            }
        }

        public class Run extends Thread {
            InputReader in;
            OutputWriter out;

            public Run(InputReader in, OutputWriter out) {
                this.in = in;
                this.out = out;
            }


            public void run() {
                int n, m;
                n = in.readInt();
                m = in.readInt();
                Graph graph = new Graph(n * 2, m * 2);
                int[][] ed = new int[n][];
                for (int i = 0; i < n; i++) {
                    int cnt = in.readInt();
                    ed[i] = new int[cnt];
                    for (int j = 0; j < cnt; j++) {
                        ed[i][j] = in.readInt();
                        ed[i][j]--;
                        graph.addWeightedEdge(i, ed[i][j] + n, 1);
                        graph.addWeightedEdge(i + n, ed[i][j], 1);
                    }
                }

                int s = in.readInt();
                s--;

                long[] distance = ShortestDistance.dijkstraAlgorithm(graph, s).first;

                for (int i = 0; i < n; i++) {

                    if (distance[i + n] != Long.MAX_VALUE && graph.firstOutbound(i + n) == -1) {
                        out.printLine("Win");
                        IntList path = ShortestDistance.dijkstraAlgorithm(graph, s, i + n).second;
                        int[] answer = new int[path.size() + 1];
                        for (int j = 0; j < path.size(); j++) {
                            answer[j] = graph.source(path.get(j)) % n + 1;
                        }
                        answer[path.size()] = i + 1;
                        out.printLine(answer);
                        return;

                    }
                }

                graph = new Graph(n, m);
                for (int i = 0; i < n; i++) for (int j = 0; j < ed[i].length; j++) graph.addSimpleEdge(i, ed[i][j]);
                int[] color = StronglyConnectedComponents.tarjan(graph);
                int[] count = new int[n];
                for (int i = 0; i < n; i++) {
                    count[color[i]]++;
                }

                distance = ShortestDistance.dijkstraAlgorithm(graph, s).first;

                for (int i = 0; i < n; i++) {
                    if (distance[i] != Long.MAX_VALUE && count[color[i]] > 1) {
                        out.print("Draw");
                        return;
                    }
                }


                out.print("Lose");

            }

        }

    }

    static interface IntStream extends Iterable<Integer>, Comparable<IntStream> {
        public IntIterator intIterator();

        default public Iterator<Integer> iterator() {
            return new Iterator<Integer>() {
                private IntIterator it = intIterator();

                public boolean hasNext() {
                    return it.isValid();
                }

                public Integer next() {
                    int result = it.value();
                    it.advance();
                    return result;
                }
            };
        }

        default public int compareTo(IntStream c) {
            IntIterator it = intIterator();
            IntIterator jt = c.intIterator();
            while (it.isValid() && jt.isValid()) {
                int i = it.value();
                int j = jt.value();
                if (i < j) {
                    return -1;
                } else if (i > j) {
                    return 1;
                }
                it.advance();
                jt.advance();
            }
            if (it.isValid()) {
                return 1;
            }
            if (jt.isValid()) {
                return -1;
            }
            return 0;
        }

    }

    static interface IntIterator {
        public int value() throws NoSuchElementException;

        public boolean advance();

        public boolean isValid();

    }

    static class Heap implements IntQueue {
        private IntComparator comparator;
        private int size = 0;
        private int[] elements;
        private int[] at;

        public Heap(int maxElement) {
            this(10, maxElement);
        }

        public Heap(IntComparator comparator, int maxElement) {
            this(10, comparator, maxElement);
        }

        public Heap(int capacity, int maxElement) {
            this(capacity, IntComparator.DEFAULT, maxElement);
        }

        public Heap(int capacity, IntComparator comparator, int maxElement) {
            this.comparator = comparator;
            elements = new int[capacity];
            at = new int[maxElement];
            Arrays.fill(at, -1);
        }

        public int size() {
            return size;
        }

        public boolean isEmpty() {
            return size == 0;
        }

        public void add(int element) {
            ensureCapacity(size + 1);
            elements[size] = element;
            at[element] = size;
            shiftUp(size++);
        }

        public void shiftUp(int index) {
            //		if (index < 0 || index >= size)
            //			throw new IllegalArgumentException();
            int value = elements[index];
            while (index != 0) {
                int parent = (index - 1) >>> 1;
                int parentValue = elements[parent];
                if (comparator.compare(parentValue, value) <= 0) {
                    elements[index] = value;
                    at[value] = index;
                    return;
                }
                elements[index] = parentValue;
                at[parentValue] = index;
                index = parent;
            }
            elements[0] = value;
            at[value] = 0;
        }

        public void shiftDown(int index) {
            if (index < 0 || index >= size) {
                throw new IllegalArgumentException();
            }
            while (true) {
                int child = (index << 1) + 1;
                if (child >= size) {
                    return;
                }
                if (child + 1 < size && comparator.compare(elements[child], elements[child + 1]) > 0) {
                    child++;
                }
                if (comparator.compare(elements[index], elements[child]) <= 0) {
                    return;
                }
                swap(index, child);
                index = child;
            }
        }

        public int getIndex(int element) {
            return at[element];
        }

        private void swap(int first, int second) {
            int temp = elements[first];
            elements[first] = elements[second];
            elements[second] = temp;
            at[elements[first]] = first;
            at[elements[second]] = second;
        }

        private void ensureCapacity(int size) {
            if (elements.length < size) {
                int[] oldElements = elements;
                elements = new int[Math.max(2 * elements.length, size)];
                System.arraycopy(oldElements, 0, elements, 0, this.size);
            }
        }

        public int poll() {
            if (isEmpty()) {
                throw new IndexOutOfBoundsException();
            }
            int result = elements[0];
            at[result] = -1;
            if (size == 1) {
                size = 0;
                return result;
            }
            elements[0] = elements[--size];
            at[elements[0]] = 0;
            shiftDown(0);
            return result;
        }


        public IntIterator intIterator() {
            return new IntIterator() {
                private int at;


                public int value() throws NoSuchElementException {
                    return elements[at];
                }


                public boolean advance() throws NoSuchElementException {
                    return ++at < size;
                }


                public boolean isValid() {
                    return at < size;
                }


                public void remove() throws NoSuchElementException {
                    throw new UnsupportedOperationException();
                }
            };
        }

    }

    static interface IntList extends IntReversableCollection {
        public abstract int get(int index);

        public abstract void set(int index, int value);

        public abstract void addAt(int index, int value);

        public abstract void removeAt(int index);

        default public void swap(int first, int second) {
            if (first == second) {
                return;
            }
            int temp = get(first);
            set(first, get(second));
            set(second, temp);
        }

        default public IntIterator intIterator() {
            return new IntIterator() {
                private int at;
                private boolean removed;

                public int value() {
                    if (removed) {
                        throw new IllegalStateException();
                    }
                    return get(at);
                }

                public boolean advance() {
                    at++;
                    removed = false;
                    return isValid();
                }

                public boolean isValid() {
                    return !removed && at < size();
                }

                public void remove() {
                    removeAt(at);
                    at--;
                    removed = true;
                }
            };
        }


        default public void add(int value) {
            addAt(size(), value);
        }

        default public void inPlaceReverse() {
            for (int i = 0, j = size() - 1; i < j; i++, j--) {
                swap(i, j);
            }
        }

    }

    static interface IntReversableCollection extends IntCollection {
    }

    static abstract class IntAbstractStream implements IntStream {

        public String toString() {
            StringBuilder builder = new StringBuilder();
            boolean first = true;
            for (IntIterator it = intIterator(); it.isValid(); it.advance()) {
                if (first) {
                    first = false;
                } else {
                    builder.append(' ');
                }
                builder.append(it.value());
            }
            return builder.toString();
        }


        public boolean equals(Object o) {
            if (!(o instanceof IntStream)) {
                return false;
            }
            IntStream c = (IntStream) o;
            IntIterator it = intIterator();
            IntIterator jt = c.intIterator();
            while (it.isValid() && jt.isValid()) {
                if (it.value() != jt.value()) {
                    return false;
                }
                it.advance();
                jt.advance();
            }
            return !it.isValid() && !jt.isValid();
        }


        public int hashCode() {
            int result = 0;
            for (IntIterator it = intIterator(); it.isValid(); it.advance()) {
                result *= 31;
                result += it.value();
            }
            return result;
        }

    }

    static interface Edge {
    }

    static interface IntCollection extends IntStream {
        public int size();

        default public void add(int value) {
            throw new UnsupportedOperationException();
        }

        default public IntCollection addAll(IntStream values) {
            for (IntIterator it = values.intIterator(); it.isValid(); it.advance()) {
                add(it.value());
            }
            return this;
        }

    }

    static class Graph {
        public static final int REMOVED_BIT = 0;
        protected int vertexCount;
        protected int edgeCount;
        private int[] firstOutbound;
        private int[] firstInbound;
        private Edge[] edges;
        private int[] nextInbound;
        private int[] nextOutbound;
        private int[] from;
        private int[] to;
        private long[] weight;
        public long[] capacity;
        private int[] reverseEdge;
        private int[] flags;

        public Graph(int vertexCount) {
            this(vertexCount, vertexCount);
        }

        public Graph(int vertexCount, int edgeCapacity) {
            this.vertexCount = vertexCount;
            firstOutbound = new int[vertexCount];
            Arrays.fill(firstOutbound, -1);

            from = new int[edgeCapacity];
            to = new int[edgeCapacity];
            nextOutbound = new int[edgeCapacity];
            flags = new int[edgeCapacity];
        }

        public int addEdge(int fromID, int toID, long weight, long capacity, int reverseEdge) {
            ensureEdgeCapacity(edgeCount + 1);
            if (firstOutbound[fromID] != -1) {
                nextOutbound[edgeCount] = firstOutbound[fromID];
            } else {
                nextOutbound[edgeCount] = -1;
            }
            firstOutbound[fromID] = edgeCount;
            if (firstInbound != null) {
                if (firstInbound[toID] != -1) {
                    nextInbound[edgeCount] = firstInbound[toID];
                } else {
                    nextInbound[edgeCount] = -1;
                }
                firstInbound[toID] = edgeCount;
            }
            this.from[edgeCount] = fromID;
            this.to[edgeCount] = toID;
            if (capacity != 0) {
                if (this.capacity == null) {
                    this.capacity = new long[from.length];
                }
                this.capacity[edgeCount] = capacity;
            }
            if (weight != 0) {
                if (this.weight == null) {
                    this.weight = new long[from.length];
                }
                this.weight[edgeCount] = weight;
            }
            if (reverseEdge != -1) {
                if (this.reverseEdge == null) {
                    this.reverseEdge = new int[from.length];
                    Arrays.fill(this.reverseEdge, 0, edgeCount, -1);
                }
                this.reverseEdge[edgeCount] = reverseEdge;
            }
            if (edges != null) {
                edges[edgeCount] = createEdge(edgeCount);
            }
            return edgeCount++;
        }

        protected final GraphEdge createEdge(int id) {
            return new GraphEdge(id);
        }

        public final int addFlowWeightedEdge(int from, int to, long weight, long capacity) {
            if (capacity == 0) {
                return addEdge(from, to, weight, 0, -1);
            } else {
                int lastEdgeCount = edgeCount;
                addEdge(to, from, -weight, 0, lastEdgeCount + entriesPerEdge());
                return addEdge(from, to, weight, capacity, lastEdgeCount);
            }
        }

        protected int entriesPerEdge() {
            return 1;
        }

        public final int addWeightedEdge(int from, int to, long weight) {
            return addFlowWeightedEdge(from, to, weight, 0);
        }

        public final int addSimpleEdge(int from, int to) {
            return addWeightedEdge(from, to, 0);
        }

        public final int vertexCount() {
            return vertexCount;
        }

        public final int firstOutbound(int vertex) {
            int id = firstOutbound[vertex];
            while (id != -1 && isRemoved(id)) {
                id = nextOutbound[id];
            }
            return id;
        }

        public final int nextOutbound(int id) {
            id = nextOutbound[id];
            while (id != -1 && isRemoved(id)) {
                id = nextOutbound[id];
            }
            return id;
        }

        public final int source(int id) {
            return from[id];
        }

        public final int destination(int id) {
            return to[id];
        }

        public final long weight(int id) {
            if (weight == null) {
                return 0;
            }
            return weight[id];
        }

        public final boolean flag(int id, int bit) {
            return (flags[id] >> bit & 1) != 0;
        }

        public final boolean isRemoved(int id) {
            return flag(id, REMOVED_BIT);
        }

        protected void ensureEdgeCapacity(int size) {
            if (from.length < size) {
                int newSize = Math.max(size, 2 * from.length);
                if (edges != null) {
                    edges = resize(edges, newSize);
                }
                from = resize(from, newSize);
                to = resize(to, newSize);
                nextOutbound = resize(nextOutbound, newSize);
                if (nextInbound != null) {
                    nextInbound = resize(nextInbound, newSize);
                }
                if (weight != null) {
                    weight = resize(weight, newSize);
                }
                if (capacity != null) {
                    capacity = resize(capacity, newSize);
                }
                if (reverseEdge != null) {
                    reverseEdge = resize(reverseEdge, newSize);
                }
                flags = resize(flags, newSize);
            }
        }

        protected final int[] resize(int[] array, int size) {
            int[] newArray = new int[size];
            System.arraycopy(array, 0, newArray, 0, array.length);
            return newArray;
        }

        private long[] resize(long[] array, int size) {
            long[] newArray = new long[size];
            System.arraycopy(array, 0, newArray, 0, array.length);
            return newArray;
        }

        private Edge[] resize(Edge[] array, int size) {
            Edge[] newArray = new Edge[size];
            System.arraycopy(array, 0, newArray, 0, array.length);
            return newArray;
        }

        public final boolean isSparse() {
            return vertexCount == 0 || edgeCount * 20 / vertexCount <= vertexCount;
        }

        protected class GraphEdge implements Edge {
            protected int id;

            protected GraphEdge(int id) {
                this.id = id;
            }

        }

    }

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

        public void printLine(int[] array) {
            print(array);
            writer.println();
        }

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

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

    }

    static interface IntQueue extends IntCollection {
    }

    static class InputReader {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private InputReader.SpaceCharFilter filter;

        public InputReader(InputStream stream) {
            this.stream = stream;
        }

        public int read() {
            if (numChars == -1) {
                throw new InputMismatchException();
            }
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0) {
                    return -1;
                }
            }
            return buf[curChar++];
        }

        public int readInt() {
            int c = read();
            while (isSpaceChar(c)) {
                c = read();
            }
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            int res = 0;
            do {
                if (c < '0' || c > '9') {
                    throw new InputMismatchException();
                }
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
        }

        public boolean isSpaceChar(int c) {
            if (filter != null) {
                return filter.isSpaceChar(c);
            }
            return isWhitespace(c);
        }

        public static boolean isWhitespace(int c) {
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        public interface SpaceCharFilter {
            public boolean isSpaceChar(int ch);

        }

    }

    static interface IntComparator {
        public static final IntComparator DEFAULT = (first, second) -> {
            if (first < second) {
                return -1;
            }
            if (first > second) {
                return 1;
            }
            return 0;
        };

        public int compare(int first, int second);

    }

    static class IntegerUtils {
        public static int longCompare(long a, long b) {
            if (a < b) {
                return -1;
            }
            if (a > b) {
                return 1;
            }
            return 0;
        }

    }

    static class IntArrayList extends IntAbstractStream implements IntList {
        private int size;
        private int[] data;

        public IntArrayList() {
            this(3);
        }

        public IntArrayList(int capacity) {
            data = new int[capacity];
        }

        public IntArrayList(IntCollection c) {
            this(c.size());
            addAll(c);
        }

        public IntArrayList(IntStream c) {
            this();
            if (c instanceof IntCollection) {
                ensureCapacity(((IntCollection) c).size());
            }
            addAll(c);
        }

        public IntArrayList(IntArrayList c) {
            size = c.size();
            data = c.data.clone();
        }

        public IntArrayList(int[] arr) {
            size = arr.length;
            data = arr.clone();
        }

        public int size() {
            return size;
        }

        public int get(int at) {
            if (at >= size) {
                throw new IndexOutOfBoundsException("at = " + at + ", size = " + size);
            }
            return data[at];
        }

        private void ensureCapacity(int capacity) {
            if (data.length >= capacity) {
                return;
            }
            capacity = Math.max(2 * data.length, capacity);
            data = Arrays.copyOf(data, capacity);
        }

        public void addAt(int index, int value) {
            ensureCapacity(size + 1);
            if (index > size || index < 0) {
                throw new IndexOutOfBoundsException("at = " + index + ", size = " + size);
            }
            if (index != size) {
                System.arraycopy(data, index, data, index + 1, size - index);
            }
            data[index] = value;
            size++;
        }

        public void removeAt(int index) {
            if (index >= size || index < 0) {
                throw new IndexOutOfBoundsException("at = " + index + ", size = " + size);
            }
            if (index != size - 1) {
                System.arraycopy(data, index + 1, data, index, size - index - 1);
            }
            size--;
        }

        public void set(int index, int value) {
            if (index >= size) {
                throw new IndexOutOfBoundsException("at = " + index + ", size = " + size);
            }
            data[index] = value;
        }

    }

    static class Pair<U, V> implements Comparable<Pair<U, V>> {
        public final U first;
        public final V second;

        public static <U, V> Pair<U, V> makePair(U first, V second) {
            return new Pair<U, V>(first, second);
        }

        private Pair(U first, V second) {
            this.first = first;
            this.second = second;
        }


        public boolean equals(Object o) {
            if (this == o) {
                return true;
            }
            if (o == null || getClass() != o.getClass()) {
                return false;
            }

            Pair pair = (Pair) o;

            return !(first != null ? !first.equals(pair.first) : pair.first != null) &&
                    !(second != null ? !second.equals(pair.second) : pair.second != null);
        }


        public int hashCode() {
            int result = first != null ? first.hashCode() : 0;
            result = 31 * result + (second != null ? second.hashCode() : 0);
            return result;
        }


        public String toString() {
            return "(" + first + "," + second + ")";
        }

        @SuppressWarnings({"unchecked"})
        public int compareTo(Pair<U, V> o) {
            int value = ((Comparable<U>) first).compareTo(o.first);
            if (value != 0) {
                return value;
            }
            return ((Comparable<V>) second).compareTo(o.second);
        }

    }

    static class StronglyConnectedComponents {
        private final Graph graph;
        private int[] order;
        private int[] lowlink;
        private int[] stack;
        private int stack_pos;
        private int color;
        private boolean[] visited;
        private int index = 0;
        private int vertexCount;
        private int[] condensed;

        private StronglyConnectedComponents(Graph graph) {
            this.graph = graph;
            vertexCount = graph.vertexCount();
            order = new int[vertexCount];
            visited = new boolean[vertexCount];
            condensed = new int[vertexCount];
        }

        public static int[] tarjan(Graph graph) {
            return new StronglyConnectedComponents(graph).tarjan();
        }

        private int[] tarjan() {
            lowlink = new int[vertexCount];
            stack = new int[vertexCount];
            index = 1;
            for (int i = 0; i < vertexCount; i++) {
                if (order[i] == 0) {
                    calculate_tarjan(i);
                }
            }
            return condensed;
        }

        private void calculate_tarjan(int node) {
            visited[node] = true;
            stack[stack_pos++] = node;
            lowlink[node] = index;
            order[node] = index;
            index++;
            int edge = graph.firstOutbound(node);
            while (edge != -1) {
                int next = graph.destination(edge);
                if (visited[next]) {
                    lowlink[node] = Math.min(lowlink[node], order[next]);
                } else if (order[next] == 0) {
                    calculate_tarjan(next);
                    lowlink[node] = Math.min(lowlink[node], lowlink[next]);
                }
                edge = graph.nextOutbound(edge);
            }
            if (lowlink[node] == order[node]) {
                int current;
                do {
                    current = stack[stack_pos - 1];
                    stack_pos--;
                    condensed[current] = color;
                    visited[current] = false;
                } while (current != node);
                color++;
            }
        }

    }

    static class ShortestDistance {
        public static Pair<long[], int[]> dijkstraAlgorithm(Graph graph, int source) {
            int vertexCount = graph.vertexCount();
            final long[] distance = new long[vertexCount];
            int[] last = new int[vertexCount];
            Arrays.fill(distance, Long.MAX_VALUE);
            Arrays.fill(last, -1);
            distance[source] = 0;
            if (graph.isSparse()) {
                Heap heap = new Heap(vertexCount, new IntComparator() {
                    public int compare(int first, int second) {
                        return IntegerUtils.longCompare(distance[first], distance[second]);
                    }
                }, vertexCount);
                heap.add(source);
                while (!heap.isEmpty()) {
                    int current = heap.poll();
                    int id = graph.firstOutbound(current);
                    while (id != -1) {
                        int next = graph.destination(id);
                        long total = graph.weight(id) + distance[current];
                        if (distance[next] > total) {
                            distance[next] = total;
                            if (heap.getIndex(next) == -1) {
                                heap.add(next);
                            } else {
                                heap.shiftUp(heap.getIndex(next));
                            }
                            last[next] = id;
                        }
                        id = graph.nextOutbound(id);
                    }
                }
            } else {
                boolean[] visited = new boolean[vertexCount];
                for (int i = 0; i < vertexCount; i++) {
                    int index = -1;
                    long length = Long.MAX_VALUE;
                    for (int j = 0; j < vertexCount; j++) {
                        if (!visited[j] && distance[j] < length) {
                            length = distance[j];
                            index = j;
                        }
                    }
                    if (index == -1) {
                        break;
                    }
                    visited[index] = true;
                    int id = graph.firstOutbound(index);
                    while (id != -1) {
                        int next = graph.destination(id);
                        if (!visited[next]) {
                            long total = graph.weight(id) + length;
                            if (distance[next] > total) {
                                distance[next] = total;
                                last[next] = id;
                            }
                        }
                        id = graph.nextOutbound(id);
                    }
                }
            }
            return Pair.makePair(distance, last);
        }

        public static Pair<Long, IntList> dijkstraAlgorithm(Graph graph, int source, int destination) {
            if (source == destination) {
                return Pair.makePair(0L, new IntArrayList());
            }
            Pair<long[], int[]> result = dijkstraAlgorithm(graph, source);
            if (result.second[destination] == -1) {
                return null;
            }
            IntList path = new IntArrayList();
            int id = destination;
            while (id != source) {
                path.add(result.second[id]);
                id = graph.source(result.second[id]);
            }
            path.inPlaceReverse();
            return Pair.makePair(result.first[destination], path);
        }

    }
}