Problem: A famous sculptor Cicasso goes to a world tour!

Well, it is not actually a world-wide. But not everyone should have the opportunity to see works of sculptor, shouldn't he? Otherwise there will be no any exclusivity. So Cicasso will entirely hold the world tour in his native country — Berland.

Cicasso is very devoted to his work and he wants to be distracted as little as possible. Therefore he will visit only four cities. These cities will be different, so no one could think that he has "favourites". Of course, to save money, he will chose the shortest paths between these cities. But as you have probably guessed, Cicasso is a weird person. Although he doesn't like to organize exhibitions, he likes to travel around the country and enjoy its scenery. So he wants the total distance which he will travel to be as large as possible. However, the sculptor is bad in planning, so he asks you for help. 

There are n cities and m one-way roads in Berland. You have to choose four different cities, which Cicasso will visit and also determine the order in which he will visit them. So that the total distance he will travel, if he visits cities in your order, starting from the first city in your list, and ending in the last, choosing each time the shortest route between a pair of cities — will be the largest. 

Note that intermediate routes may pass through the cities, which are assigned to the tour, as well as pass twice through the same city. For example, the tour can look like that: <image>. Four cities in the order of visiting marked as overlines: [1, 5, 2, 4].

Note that Berland is a high-tech country. So using nanotechnologies all roads were altered so that they have the same length. For the same reason moving using regular cars is not very popular in the country, and it can happen that there are such pairs of cities, one of which generally can not be reached by car from the other one. However, Cicasso is very conservative and cannot travel without the car. Choose cities so that the sculptor can make the tour using only the automobile. It is guaranteed that it is always possible to do. 

Input

In the first line there is a pair of integers n and m (4 ≤ n ≤ 3000, 3 ≤ m ≤ 5000) — a number of cities and one-way roads in Berland.

Each of the next m lines contains a pair of integers ui, vi (1 ≤ ui, vi ≤ n) — a one-way road from the city ui to the city vi. Note that ui and vi are not required to be distinct. Moreover, it can be several one-way roads between the same pair of cities. 

Output

Print four integers — numbers of cities which Cicasso will visit according to optimal choice of the route. Numbers of cities should be printed in the order that Cicasso will visit them. If there are multiple solutions, print any of them.

Example

Input

8 9
1 2
2 3
3 4
4 1
4 5
5 6
6 7
7 8
8 5


Output

2 1 8 7

Note

Let d(x, y) be the shortest distance between cities x and y. Then in the example d(2, 1) = 3, d(1, 8) = 7, d(8, 7) = 3. The total distance equals 13. 

Solution (in JAVA):

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

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
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);
        TaskB solver = new TaskB();
        solver.solve(1, in, out);
        out.close();
    }

    static class TaskB {
        public void solve(int testNumber, InputReader in, OutputWriter out) {
            int n, m;
            Graph gr;
            final int inf = (int) 1e8;

            //
            n = in.readInt();
            m = in.readInt();
            gr = new Graph(n, m);
            for (int i = 0; i < m; i++) {
                int a = in.readInt() - 1;
                int b = in.readInt() - 1;
                gr.addSimpleEdge(a, b);
            }
        /**/
//        n = (int) 3e3;
//        m = (int) 5e3;
//        gr = new Graph(n, m);
//        ExtendedRandom rnd = new ExtendedRandom(228);
//        for (int i = 0; i < m; i++) {
//            int a = rnd.nextInt(n);
//            int b = rnd.nextInt(n);
//            gr.addSimpleEdge(a, b);
//        }

            int[][] dist = new int[n][n];
            IntQueue Q = new IntArrayQueue(n);
            for (int s = 0; s < n; s++) {
                int[] dp = dist[s];
                Arrays.fill(dp, inf);
                dp[s] = 0;
                Q.add(s);
                while (!Q.isEmpty()) {
                    int v = Q.poll();
                    for (int id = gr.firstOutbound(v); id != -1; id = gr.nextOutbound(id)) {
                        int to = gr.destination(id);
                        if (dp[to] == inf) {
                            dp[to] = dp[v] + 1;
                            Q.add(to);
                        }
                    }
                }
            }

            IntArrayList[] bestOut = new IntArrayList[n];
            IntArrayList[] bestIn = new IntArrayList[n];
            for (int s = 0; s < n; s++) {
                bestOut[s] = new IntArrayList(3);
                bestIn[s] = new IntArrayList(3);
                int m0, m1, m2;

                m0 = m1 = m2 = s;
                for (int i = 0; i < n; i++) {
                    if (dist[s][i] == inf) {
                        continue;
                    }
                    if (dist[s][m0] < dist[s][i]) {
                        m2 = m1;
                        m1 = m0;
                        m0 = i;
                    } else if (dist[s][m1] < dist[s][i]) {
                        m2 = m1;
                        m1 = i;
                    } else if (dist[s][m2] < dist[s][i]) {
                        m2 = i;
                    }
                }
                if (m0 != s) {
                    bestOut[s].add(m0);
                }
                if (m1 != s) {
                    bestOut[s].add(m1);
                }
                if (m2 != s) {
                    bestOut[s].add(m2);
                }


                m0 = m1 = m2 = s;
                for (int i = 0; i < n; i++) {
                    if (dist[i][s] == inf) {
                        continue;
                    }
                    if (dist[m0][s] < dist[i][s]) {
                        m2 = m1;
                        m1 = m0;
                        m0 = i;
                    } else if (dist[m1][s] < dist[i][s]) {
                        m2 = m1;
                        m1 = i;
                    } else if (dist[m2][s] < dist[i][s]) {
                        m2 = i;
                    }
                }
                if (m0 != s) {
                    bestIn[s].add(m0);
                }
                if (m1 != s) {
                    bestIn[s].add(m1);
                }
                if (m2 != s) {
                    bestIn[s].add(m2);
                }
            }

            //
            int maxLen = -1;
            int bestA = -1;
            int bestI = -1;
            int bestJ = -1;
            int bestZ = -1;
            for (int i = 0; i < n; i++) {
                for (int j = 0; j < n; j++) {
                    if (i == j) {
                        continue;
                    }
                    if (dist[i][j] == inf) {
                        continue;
                    }
                    for (int ind0 = 0; ind0 < bestIn[i].size(); ind0++) {
                        int a = bestIn[i].get(ind0);
                        if (a == i || a == j) {
                            continue;
                        }
                        for (int ind1 = 0; ind1 < bestOut[j].size(); ind1++) {
                            int z = bestOut[j].get(ind1);
                            if (z == i || z == j || z == a) {
                                continue;
                            }
                            int len = dist[a][i] + dist[i][j] + dist[j][z];
                            if (inf <= len) {
                                continue;
                            }
                            if (maxLen < len) {
                                maxLen = len;
                                bestA = a;
                                bestI = i;
                                bestJ = j;
                                bestZ = z;
                            }
                        }
                    }
                }
            }
            out.printLine(bestA + 1, bestI + 1, bestJ + 1, bestZ + 1);
        /**/
        }

    }

    static interface IntQueue extends IntCollection {
        public int poll();

    }

    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--;
        }

    }

    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 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 class IntArrayQueue implements IntQueue {
        private int[] data;
        private int from;
        private int to;

        public IntArrayQueue(int capacity) {
            data = new int[Integer.highestOneBit(capacity) << 1];
        }

        public IntArrayQueue() {
            this(3);
        }

        public IntArrayQueue(int[] array) {
            this(array.length);
            to = array.length;
            System.arraycopy(array, 0, data, 0, to);
        }

        public IntArrayQueue(IntStream s) {
            addAll(s);
        }

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

        public int size() {
            return (to - from) & (data.length - 1);
        }

        public void add(int v) {
            ensureCapacity(size() + 1);
            data[to++] = v;
            to &= data.length - 1;
        }

        public int poll() {
            if (from == to) {
                throw new NoSuchElementException();
            }
            int result = data[from++];
            from &= data.length - 1;
            return result;
        }

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

                public int value() {
                    if (at == to) {
                        throw new NoSuchElementException();
                    }
                    return data[at];
                }

                public boolean advance() {
                    if (!isValid()) {
                        throw new NoSuchElementException();
                    }
                    at++;
                    at &= data.length - 1;
                    return isValid();
                }

                public boolean isValid() {
                    return at != to;
                }

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

        private void ensureCapacity(int capacity) {
            if (data.length <= capacity) {
                int[] newData = new int[Integer.highestOneBit(capacity) << 1];
                if (from <= to) {
                    System.arraycopy(data, from, newData, 0, size());
                } else {
                    System.arraycopy(data, from, newData, 0, data.length - from);
                    System.arraycopy(data, 0, newData, data.length - from, to);
                }
                to = size();
                from = 0;
                data = newData;
            }
        }

    }

    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 IntCollection extends IntStream {
        public int size();

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

        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 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 destination(int id) {
            return to[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;
        }

        protected class GraphEdge implements Edge {
            protected int id;

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

        }

    }

    static interface IntReversableCollection extends IntCollection {
    }

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

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

    }

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

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

        public abstract void removeAt(int index);

        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);
        }

    }

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

        public boolean advance();

        public boolean isValid();

    }
}