Problem: You are given an array of n elements, you must make it a co-prime array in as few moves as possible.

In each move you can insert any positive integral number you want not greater than 109 in any place in the array.

An array is co-prime if any two adjacent numbers of it are co-prime.

In the number theory, two integers a and b are said to be co-prime if the only positive integer that divides both of them is 1.

Input

The first line contains integer n (1 ≤ n ≤ 1000) — the number of elements in the given array.

The second line contains n integers ai (1 ≤ ai ≤ 109) — the elements of the array a.

Output

Print integer k on the first line — the least number of elements needed to add to the array a to make it co-prime.

The second line should contain n + k integers aj — the elements of the array a after adding k elements to it. Note that the new array should be co-prime, so any two adjacent values should be co-prime. Also the new array should be got from the original array a by adding k elements to it.

If there are multiple answers you can print any one of them.

Example

Input

3
2 7 28


Output

1
2 7 9 28

Solution (in JAVA):

Solution:
import java.io.*;
import java.util.*;

// printArr() - prints the array
// intList, doubleList, longList
// nextIntArray

/* stuff you should look for
 * int overflow, array bounds
 * special cases (n=1?)
 * do smth instead of nothing and stay organized
 * WRITE STUFF DOWN
 */

public class current {
    public static void main(String[] args) {
        FastReader fr = new FastReader();
        fr.nextLine();
        solve(fr.nextIntArray());
    }

    public static void solve(int[] arr) {
        int l = arr.length;
        Map<Integer, Integer> map = new HashMap<>();
        for (int i = 1; i < l; i++) {
            if (isRelativelyPrime(arr[i], arr[i-1])) {
                continue;
            }
            map.put(i, 1);
        }
        System.out.println(map.size());
        for (int i = 0; i < l; i++) {
            if (map.containsKey(i)) {
                System.out.print(map.get(i) + " ");
            }
            System.out.print(arr[i] + " ");
        }
        System.out.println();
    }

    public static boolean isRelativelyPrime(int a, int b) {
        double c = Math.min(Math.sqrt(a), Math.sqrt(b));
        if (a == 1 || b == 1) {
            return true;
        }
        if (Math.max(a, b) % Math.min(a, b) == 0) {
            return false;
        }
        int min = Math.min(a, b);
        int[] arr = new int[(int) (c-1)];
        for (int i = 2; i <= c; i++) {
            if (a % i == 0 && b % i == 0) {
                return false;
            }
            if (min % i == 0) {
                arr[i - 2] = min / i;
            }
        }
        for (int i : arr) {
            if (i != 0) {
                if (a % i == 0 && b % i == 0) {
                    return false;
                }
            }
        }
        return true;
    }

    public static Set<Integer> get(List<Set<Integer>> graph, int i) {
        try {
            return graph.get(i);
        } catch (IndexOutOfBoundsException e) {
            return new HashSet<>();
        }
    }

    public static void printArr(int[] a) {
        System.out.println(Arrays.toString(a));
    }

    public static int[] bfs(List<Set<Integer>> graph, int v) {
        int l = graph.size();
        Deque<Integer> list = new ArrayDeque<>();
        list.add(v);
        boolean[] seen = new boolean[l];
        int distance = 0;
        int node = v;
        int size = 1;
        int index = 0;
        // Iterate over every single vertice and edge
        // O(V+E) -> O(V) for trees
        while (!list.isEmpty()) {
            int cur = list.poll();
            seen[cur] = true;
            node = cur;

            index++;
            if (index > size) {
                distance++;
                size = list.size();
                index = 0;
            }

            for (int i : graph.get(cur)) {
                if (!seen[i]) {
                    seen[i] = true;
                    list.add(i);
                }
            }
        }
        return new int[]{node, distance};
    }

    static class SegTree {
        int startIndex, endIndex;
        long sum;
        SegTree lchild, rchild;

        SegTree(int[] arr) {this(0, arr.length-1, arr);}

        SegTree(int startIndex, int endIndex, int[] arr) {
            this.startIndex = startIndex;
            this.endIndex = endIndex;
            if (startIndex == endIndex) sum = arr[startIndex];
            else {
                int mid = (startIndex + endIndex) / 2;
                lchild = new SegTree(startIndex, mid, arr);
                rchild = new SegTree(mid + 1, endIndex, arr);
                sum = lchild.sum + rchild.sum;
                recalc();
            }
        }

        void recalc() {
            if (startIndex == endIndex) return; sum = lchild.sum + rchild.sum;
        }

        public void valueUpdate(int index, int value) {
            if (startIndex == endIndex) {sum = value; return;}
            if (index > lchild.endIndex) rchild.valueUpdate(index, value); else lchild.valueUpdate(index, value); recalc();
        }

        public long rangeSum(int startIndex, int endIndex) {
            if (endIndex < this.startIndex || startIndex > this.endIndex) return 0;
            if (startIndex <= this.startIndex && endIndex >= this.endIndex) return sum;
            return lchild.rangeSum(startIndex, endIndex) + rchild.rangeSum(startIndex, endIndex);
        }
    }

    public static double sum(List<Long> n) {
        double a = 0;
        for (long i : n) {
            a += i;
        }
        return a;
    }

    public static int toInt(String n) {
        return Integer.parseInt(n);
    }

    public static double toDouble(String n) {
        return Double.parseDouble(n);
    }

    public static long toLong(String n) {
        return Long.parseLong(n);
    }

    static class FastReader {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st;

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

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

        double nextDouble() {
            return Double.parseDouble(next());
        }

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

        String nextLine() {
            String a = "";
            try {
                a = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return a;
        }

        int[] nextIntArray() {
            return intArray(nextLine().split(" "));
        }

        long[] nextLongArray() {
            return longArray(nextLine().split(" "));
        }

        double[] nextDoubleArray() {
            return doubleArray(nextLine().split(" "));
        }

        public int getInt(int index) {
            String[] arr = nextLine().split(" ");
            return Integer.parseInt(arr[index]);
        }

        public long getLong(int index) {
            String[] arr = nextLine().split(" ");
            return Long.parseLong(arr[index]);
        }

        public double getDouble(int index) {
            String[] arr = nextLine().split(" ");
            return Double.parseDouble(arr[index]);
        }

        public List<String> stringList() {
            String[] arr = nextLine().split(" ");
            return Arrays.asList(arr);
        }

        public List<Integer> intList() {
            String[] arr = nextLine().split(" ");
            List<Integer> a = new ArrayList<>();
            for (String i : arr) {
                a.add(Integer.parseInt(i));
            }
            return a;
        }

        public List<Double> doubleList() {
            String[] arr = nextLine().split(" ");
            List<Double> a = new ArrayList<>();
            for (String i : arr) {
                a.add(Double.parseDouble(i));
            }
            return a;
        }

        public List<Long> longList() {
            String[] arr = nextLine().split(" ");
            List<Long> a = new ArrayList<>();
            for (String i : arr) {
                a.add(Long.parseLong(i));
            }
            return a;
        }
    }


    public static int[] intArray(String[] arr) {
        int l = arr.length;
        int[] a = new int[l];
        for (int i = 0; i < l; i++) {
            a[i] = Integer.parseInt(arr[i]);
        }
        return a;
    }

    public static long[] longArray(String[] arr) {
        int l = arr.length;
        long[] a = new long[l];
        for (int i = 0; i < l; i++) {
            a[i] = Long.parseLong(arr[i]);
        }
        return a;
    }

    public static double[] doubleArray(String[] arr) {
        int l = arr.length;
        double[] a = new double[l];
        for (int i = 0; i < l; i++) {
            a[i] = Double.parseDouble(arr[i]);
        }
        return a;
    }
}