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 java.util.stream.Collectors;

public class D2 {

    public static void main(String[] args) {

        FastScanner sc = new FastScanner();
        int t = 1;
        while(t-- > 0) {
            int n = sc.nextInt();
            int ar[] = sc.nextIntArray(n);
            sort(ar);
            int ans[] = new int[n];
            int j = 1;
            boolean skipped[] = new boolean[n];
            for(int i = 0; i < (n-1) / 2 && j < n; i++) {
                ans[j] = ar[i];
                j += 2;
            }

            j = 0;
            int i = (n-1) / 2;
            int maxPos = i * 2 + 1;
            while(i < n) {

                if(ans[j] > 0) {
                    j++;
                    continue;
                }
                int prev = j-1 >= 0 ? ans[j-1] : Integer.MIN_VALUE;
                int next = j+1 < n ? ans[j+1] : Integer.MIN_VALUE;
                while(i < n && ar[i] <= max(prev, next)) {
                    skipped[i] = true;
                    i++;
                }
                if(i >= n)
                    break;
                ans[j++] = ar[i++];
            }

            while(j < n && i < n) {

                ans[j] = ar[i++];
                while(j < n && ans[j] > 0)
                    j++;
            }

            for(i = 0; i < n; i++) {
                if (skipped[i])
                    ans[j] = ar[i];
                while(j < n && ans[j] > 0)
                    j++;
            }

            int x = 0;
            for (i = 1; i < n - 1; i++)
                if (ans[i] < ans[i - 1] && ans[i] < ans[i + 1])
                    x++;
            println(x);
            println(ans);
        }
    }

    static final Random random = new Random();

    static class FastScanner {
        private InputStream sin = System.in;
        private final byte[] buffer = new byte[1024];
        private int ptr = 0;
        private int buflen = 0;
        public FastScanner(){}
        public FastScanner(String filename) throws FileNotFoundException {
            File file = new File(filename);
            sin = new FileInputStream(file);
        }
        private boolean hasNextByte() {
            if (ptr < buflen) {
                return true;
            }else{
                ptr = 0;
                try {
                    buflen = sin.read(buffer);
                } catch (IOException e) {
                    e.printStackTrace();
                }
                if (buflen <= 0) {
                    return false;
                }
            }
            return true;
        }
        private int readByte() { if (hasNextByte()) return buffer[ptr++]; else return -1;}
        private static boolean isPrintableChar(int c) { return 33 <= c && c <= 126;}
        public boolean hasNext() { while(hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++; return hasNextByte();}
        public String next() {
            if (!hasNext()) throw new NoSuchElementException();
            StringBuilder sb = new StringBuilder();
            int b = readByte();
            while(isPrintableChar(b)) {
                sb.appendCodePoint(b);
                b = readByte();
            }
            return sb.toString();
        }
        public long nextLong() {
            if (!hasNext()) throw new NoSuchElementException();
            long n = 0;
            boolean minus = false;
            int b = readByte();
            if (b == '-') {
                minus = true;
                b = readByte();
            }
            if (b < '0' || '9' < b) {
                throw new NumberFormatException();
            }
            while(true){
                if ('0' <= b && b <= '9') {
                    n *= 10;
                    n += b - '0';
                }else if(b == -1 || !isPrintableChar(b) || b == ':'){
                    return minus ? -n : n;
                }else{
                    throw new NumberFormatException();
                }
                b = readByte();
            }
        }
        public int nextInt() {
            long nl = nextLong();
            if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE) throw new NumberFormatException();
            return (int) nl;
        }
        public double nextDouble() { return Double.parseDouble(next());}
        public long[] nextLongArray(final int n){
            final long[] a = new long[n];
            for (int i = 0; i < n; i++)
                a[i] = nextLong();
            return a;
        }
        public int[] nextIntArray(final int n){
            final int[] a = new int[n];
            for (int i = 0; i < n; i++)
                a[i] = nextInt();
            return a;
        }
        public double[] nextDoubleArray(final int n){
            final double[] a = new double[n];
            for (int i = 0; i < n; i++)
                a[i] = nextDouble();
            return a;
        }

        public List<Integer>[] adjacencyList(int nodes, int edges) {
            return adjacencyList(nodes, edges, false);
        }
        public List<Integer>[] adjacencyList(int nodes, int edges, boolean isDirected) {

            List<Integer>[] adj = new ArrayList[nodes + 1];
            Arrays.setAll(adj, (i) -> new ArrayList<>());
            for (int i = 0; i < edges; i++) {
                int a = nextInt(), b = nextInt();
                adj[a].add(b);
                if (!isDirected) adj[b].add(a);
            }
            return adj;
        }
    }

    static int findDistance(List<Integer> G[], int nodes, int src, int dst) {

        LinkedList<Integer> queue = new LinkedList<>();
        int dist[] = new int[nodes + 1];
        int ans = -1;
        dist[src] = 0;
        queue.add(src);
        while(queue.size() > 0) {
            int u = queue.poll();
            if(u == dst) {
                ans = dist[u];
            }
            for(int v : G[u]) {
                if(dist[v] >= 0)
                    continue;
                queue.add(v);
                dist[v] = dist[u] + 1;
            }
        }
        return ans;
    }

    static void sort(int A[]) {
        shuffleArray(A);
        Arrays.sort(A);
    }
    static void sort(long A[]) {
        shuffleArray(A);
        Arrays.sort(A);
    }
    static void sort(double A[]) {
        shuffleArray(A);
        Arrays.sort(A);
    }
    static void shuffleArray(int[] A) {
        int n = A.length;
        for(int i = 0; i < n; i++) {
            int tmp = A[i];
            int randomPos = i + random.nextInt(n-i);
            A[i] = A[randomPos];
            A[randomPos] = tmp;
        }
    }
    static void shuffleArray(long[] A) {
        int n = A.length;
        for(int i = 0; i < n; i++) {
            long tmp = A[i];
            int randomPos = i + random.nextInt(n-i);
            A[i] = A[randomPos];
            A[randomPos] = tmp;
        }
    }
    static void shuffleArray(double[] A) {
        int n = A.length;
        for(int i = 0; i < n; i++) {
            double tmp = A[i];
            int randomPos = i + random.nextInt(n-i);
            A[i] = A[randomPos];
            A[randomPos] = tmp;
        }
    }

    static int[] subArray(int A[], int x, int y) {
        int B[] = new int[y - x + 1];
        for(int i = x; i <= y; i++)
            B[i-x] = A[i];
        return B;
    }

    static int[] toArray(List<Integer> L) {
        return L.stream().mapToInt(x -> x).toArray();
    }

    static void println(int[] A) {
        for(int e: A) System.out.print(e + " ");
        System.out.println();
    }

    static void println(long[] A) {
        for(long e: A) System.out.print(e + " ");
        System.out.println();
    }

    static void println(List arr) {
        for(Object e: arr) System.out.print(e + " ");
        System.out.println();
    }

    static void print(String s) {
        System.out.print(s);
    }

    static void println(String s) {
        System.out.println(s);
    }
    static void println(long n) {
        System.out.println(n);
    }

    static List<Integer> toList(int ar[]) {
        return Arrays.stream(ar).boxed().collect(Collectors.toList());
    }

    static List<Long> toList(long ar[]) {
        return Arrays.stream(ar).boxed().collect(Collectors.toList());
    }

    static List<Double> toList(double ar[]) {
        return Arrays.stream(ar).boxed().collect(Collectors.toList());
    }

    static long gcd(long a, long b) {
        if(b == 0)
            return a;
        return gcd(b, a % b);
    }

    private static int abs(int a){  return (a>=0) ? a: -a;  }
    private static int min(int... ins){ return Arrays.stream(ins).min().getAsInt(); }
    private static int max(int... ins){ return Arrays.stream(ins).max().getAsInt(); }
    private static int sum(int... ins){ return Arrays.stream(ins).sum(); }
    private static long abs(long a){ return (a>=0) ? a: -a; }
    private static long min(long... ins){ return Arrays.stream(ins).min().getAsLong(); }
    private static long max(long... ins){ return Arrays.stream(ins).max().getAsLong(); }
    private static long sum(long... ins){ return Arrays.stream(ins).sum(); }
    private static double abs(double a){ return (a>=0) ? a: -a; }
    private static double min(double... ins){ return Arrays.stream(ins).min().getAsDouble(); }
    private static double max(double... ins){ return Arrays.stream(ins).max().getAsDouble(); }
    private static double sum(double... ins){ return Arrays.stream(ins).sum(); }

    private static class Pair implements Comparable<Pair> {
        int x, y;
        Pair(int x, int y) { this.x = x; this.y = y; }
        Pair() {}

        @Override
        public int compareTo(Pair other) {
            return x == other.x ? y - other.y : x - other.x;
        }

        @Override
        public boolean equals(Object o) {
            if (this == o) return true;
            if (o == null || getClass() != o.getClass()) return false;
            Pair pair = (Pair) o;
            return x == pair.x &&
                    y == pair.y;
        }

        @Override
        public int hashCode() {
            return Objects.hash(x, y);
        }
    }

    static int lowerBound(int ar[], int L, int R, int val) {
        if(val <= ar[L])
            return L;
        if(val > ar[R])
            return R;
        while(L <= R) {
            int mid = (L + R) / 2;
            if(ar[mid] >= val)
                R = mid - 1;
            else
                L = mid + 1;
        }
        return L;
    }

    static int upperBound(int ar[], int L, int R, int val) {
        if(val < ar[L])
            return L;
        if(val >= ar[R])
            return R;
        while(L <= R) {
            int mid = (L + R) / 2;
            if(ar[mid] > val)
                R = mid - 1;
            else
                L = mid + 1;
        }
        return R;
    }
}