This is the easy version of the problem. The difference between the versions is that in the easy version all prices a_i are different. You can make hacks if and only if you solved both versions of the problem.

Today is Sage's birthday, and she will go shopping to buy ice spheres. All n ice spheres are placed in a row and they are numbered from 1 to n from left to right. Each ice sphere has a positive integer price. In this version all prices are different.

An ice sphere is cheap if it costs strictly less than two neighboring ice spheres: the nearest to the left and the nearest to the right. The leftmost and the rightmost ice spheres are not cheap. Sage will choose all cheap ice spheres and then buy only them.

You can visit the shop before Sage and reorder the ice spheres as you wish. Find out the maximum number of ice spheres that Sage can buy, and show how the ice spheres should be reordered.

Input

The first line contains a single integer n (1 ≤ n ≤ 10^5) — the number of ice spheres in the shop.

The second line contains n different integers a_1, a_2, ..., a_n (1 ≤ a_i ≤ 10^9) — the prices of ice spheres.

Output

In the first line print the maximum number of ice spheres that Sage can buy.

In the second line print the prices of ice spheres in the optimal order. If there are several correct answers, you can print any of them.

Example

Input


5
1 2 3 4 5


Output


2
3 1 4 2 5 

Note

In the example it's not possible to place ice spheres in any order so that Sage would buy 3 of them. If the ice spheres are placed like this (3, 1, 4, 2, 5), then Sage will buy two spheres: one for 1 and one for 2, because they are cheap.
import java.io.*;
import java.util.*;

import static java.util.Collections.*;
import static java.lang.Math.*;
import static java.util.Arrays.*;

public class cf {

    private static final int MOD = (int) (1e9 + 7), MOD_FFT = 998244353;
    private static final Reader r = new Reader();
    private static final PrintWriter out = new PrintWriter(new BufferedOutputStream(System.out));
    private static final boolean thread = false;
    static final boolean HAS_TEST_CASES = false;
    static final int SCAN_LINE_LENGTH = 1000002;

    static int n, a[], e[][];

    private static Vector<Integer> adj[], v = new Vector<>();

    static void solve() throws Exception {
        int n = ni();
        a = na(n);

        sort(a);
        int b[] = new int[n];
        for (int i = 0, j = (n) / 2, k = 0; k < n; k++) {
            if (k % 2 == 0)
                b[k] = a[j++];
            else
                b[k] = a[i++];
        }

        int ans = 0;
        for (int k = 1; k < b.length - 1; k++) {
            if (b[k - 1] > b[k] && b[k] < b[k + 1])
                ans++;
        }
        pn(ans);
        for (int i : b) {
            p(i + " ");
        }
        pn();
    }

    public static void main(final String[] args) throws Exception {
        if (!thread) {
            final int testcases = HAS_TEST_CASES ? ni() : 1;
            for (int i = 1; i <= testcases; i++) {
                // pni(i + " t");
                // out.print("Case #" + (i + 1) + ": ");
                try {
                    solve();
                } catch (final Exception e) {
                    // pni("idk Exception");
                    // e.printStackTrace(System.err);
                    // System.exit(0);
                    throw e;
                }
            }
            out.flush();
        }
        r.close();
        out.close();
    }

    private static void swap(final int i, final int j) {
        final int temp = a[i];
        a[i] = a[j];
        a[j] = temp;
    }

    private static boolean isMulOverflow(final long A, final long B) {
        if (A == 0 || B == 0)
            return false;
        final long result = A * B;
        if (A == result / B)
            return true;
        return false;
    }

    private static int gcd(final int a, final int b) {
        if (b == 0)
            return a;
        return gcd(b, a % b);
    }

    private static class Pair<T, E> implements Comparable<Pair<T, E>> {
        T fir;
        E snd;

        Pair() {
        }

        Pair(final T x, final E y) {
            this.fir = x;
            this.snd = y;
        }

        @Override
        @SuppressWarnings("unchecked")
        public int compareTo(final Pair<T, E> o) {
            final int c = ((Comparable<T>) fir).compareTo(o.fir);
            return c != 0 ? c : ((Comparable<E>) snd).compareTo(o.snd);
        }

    }

    private static class pi implements Comparable<pi> {
        int fir, snd;

        pi() {
        }

        pi(final int a, final int b) {
            fir = a;
            snd = b;
        }

        public int compareTo(final pi o) {
            return fir == o.fir ? snd - o.snd : fir - o.fir;
        }

    }

    private static <T> void checkV(final Vector<T> adj[], final int i) {
        adj[i] = adj[i] == null ? new Vector<>() : adj[i];
    }

    private static int[] na(final int n) throws Exception {
        final int[] a = new int[n];
        for (int i = 0; i < n; i++) {
            a[i] = ni();
        }
        return a;
    }

    private static int[] na1(final int n) throws Exception {
        final int[] a = new int[n + 1];
        for (int i = 1; i < a.length; i++) {
            a[i] = ni();
        }
        return a;
    }

    private static String n() throws IOException {
        return r.readToken();
    }

    private static String nln() throws IOException {
        return r.readLine();
    }

    private static int ni() throws IOException {
        return r.nextInt();
    }

    private static long nl() throws IOException {
        return r.nextLong();
    }

    private static double nd() throws IOException {
        return r.nextDouble();
    }

    private static void p(final Object o) {
        out.print(o);
    }

    private static void pn(final Object o) {
        out.println(o);
    }

    private static void pn() {
        out.println("");
    }

    private static void pi(final Object o) {
        out.print(o);
        out.flush();
    }

    private static void pni() {
        out.println("");
        out.flush();
    }

    private static void pni(final Object o) {
        out.println(o);
        out.flush();
    }

    private static class Reader {
        private final int BUFFER_SIZE = 1 << 17;
        private final DataInputStream din;
        private final byte[] buffer;
        private int bufferPointer, bytesRead;
        // private StringTokenizer st;

        public Reader() {
            din = new DataInputStream(System.in);
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        }

        public Reader(final String file_name) throws IOException {
            din = new DataInputStream(new FileInputStream(file_name));
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        }

        final byte[] buf = new byte[SCAN_LINE_LENGTH];

        public String readLine() throws IOException {
            int cnt = 0;
            int c;
            o: while ((c = read()) != -1) {
                if (c == '\n')
                    if (cnt == 0)
                        continue o;
                    else
                        break;
                buf[cnt++] = (byte) c;
            }
            return new String(buf, 0, cnt);
        }

        public String readToken() throws IOException {
            int cnt = 0;
            int c;
            o: while ((c = read()) != -1) {
                if (!(c >= 33 && c <= 126))
                    if (cnt == 0)
                        continue o;
                    else
                        break;
                buf[cnt++] = (byte) c;
            }
            return new String(buf, 0, cnt);
        }

        public int nextInt() throws IOException {
            int ret = 0;
            byte c = read();
            while (c <= ' ')
                c = read();
            final boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');

            if (neg)
                return -ret;
            return ret;
        }

        public long nextLong() throws IOException {
            long ret = 0;
            byte c = read();
            while (c <= ' ')
                c = read();
            final boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
            if (neg)
                return -ret;
            return ret;
        }

        public double nextDouble() throws IOException {
            double ret = 0, div = 1;
            byte c = read();
            while (c <= ' ')
                c = read();
            final boolean neg = (c == '-');
            if (neg)
                c = read();

            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');

            if (c == '.') {
                while ((c = read()) >= '0' && c <= '9') {
                    ret += (c - '0') / (div *= 10);
                }
            }

            if (neg)
                return -ret;
            return ret;
        }

        private void fillBuffer() throws IOException {
            bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE);
            if (bytesRead == -1)
                buffer[0] = -1;
        }

        private byte read() throws IOException {
            if (bufferPointer == bytesRead)
                fillBuffer();
            return buffer[bufferPointer++];
        }

        public void close() throws IOException {
            if (din == null)
                return;
            din.close();
        }
    }

    static {
        if (thread)
            new Thread(null, new Runnable() {
                @Override
                public void run() {
                    try {
                        final int testcases = HAS_TEST_CASES ? ni() : 1;
                        for (int i = 1; i <= testcases; i++) {
                            // out.print("Case #" + (i + 1) + ": ");
                            try {
                                solve();
                            } catch (final ArrayIndexOutOfBoundsException e) {
                                e.printStackTrace(System.err);
                                System.exit(-1);
                            } catch (final Exception e) {
                                pni("idk Exception in solve");
                                e.printStackTrace(System.err);
                                System.exit(-1);
                            }
                        }
                        out.flush();
                    } catch (final Throwable t) {
                        t.printStackTrace(System.err);
                        System.exit(-1);
                    }
                }
            }, "rec", (1L << 28)).start();
    }

    @SuppressWarnings({ "unchecked", })
    private static <T> T deepCopy(final T old) {
        try {
            return (T) deepCopyObject(old);
        } catch (final IOException | ClassNotFoundException e) {
            e.printStackTrace(System.err);
            System.exit(-1);
        }
        return null;
    }

    private static Object deepCopyObject(final Object oldObj) throws IOException, ClassNotFoundException {
        ObjectOutputStream oos = null;
        ObjectInputStream ois = null;
        try {
            final ByteArrayOutputStream bos = new ByteArrayOutputStream(); // A
            oos = new ObjectOutputStream(bos); // B
            // serialize and pass the object
            oos.writeObject(oldObj); // C
            oos.flush(); // D
            final ByteArrayInputStream bin = new ByteArrayInputStream(bos.toByteArray()); // E
            ois = new ObjectInputStream(bin); // F
            // return the new object
            return ois.readObject(); // G
        } catch (final ClassNotFoundException e) {
            pni("Exception in ObjectCloner = " + e);
            throw (e);
        } finally {
            oos.close();
            ois.close();
        }
    }

}