Given an array a of length n, find another array, b, of length n such that:

  * for each i (1 ≤ i ≤ n) MEX(\\{b_1, b_2, …, b_i\})=a_i. 



The MEX of a set of integers is the smallest non-negative integer that doesn't belong to this set.

If such array doesn't exist, determine this.

Input

The first line contains an integer n (1 ≤ n ≤ 10^5) — the length of the array a.

The second line contains n integers a_1, a_2, …, a_n (0 ≤ a_i ≤ i) — the elements of the array a. It's guaranteed that a_i ≤ a_{i+1} for 1≤ i < n.

Output

If there's no such array, print a single line containing -1.

Otherwise, print a single line containing n integers b_1, b_2, …, b_n (0 ≤ b_i ≤ 10^6)

If there are multiple answers, print any.

Examples

Input


3
1 2 3


Output


0 1 2 

Input


4
0 0 0 2


Output


1 3 4 0 

Input


3
1 1 3


Output


0 2 1 

Note

In the second test case, other answers like [1,1,1,0], for example, are valid.
/***
 *    ██████╗=====███████╗====███████╗====██████╗=
 *    ██╔══██╗====██╔════╝====██╔════╝====██╔══██╗
 *    ██║==██║====█████╗======█████╗======██████╔╝
 *    ██║==██║====██╔══╝======██╔══╝======██╔═══╝=
 *    ██████╔╝====███████╗====███████╗====██║=====
 *    ╚═════╝=====╚══════╝====╚══════╝====╚═╝=====
 *    ============================================
 */

import sun.misc.IOUtils;
import sun.nio.cs.KOI8_U;

import java.io.*;
import java.util.*;
import java.math.*;
import java.lang.*;

public class AA implements Runnable {


    public void run() {
        InputReader sc = new InputReader();
        PrintWriter out = new PrintWriter(System.out);
        int i=0,j=0,k=0;
        int t=0;
        //t=sc.nextInt();
        for(int testcase = 0;testcase < t; testcase++)
        {
        }

        int n=sc.nextInt();
        int arr[]=new int[n];
        int ans[]=new int[n];
        Arrays.fill(ans,-1);
        boolean present[]=new boolean[n];
        for (i=0;i<n;i++)
        {
            arr[i]=sc.nextInt();
            if (i>0)
                if (arr[i-1]!=arr[i])
                {
                    ans[i]=arr[i-1];
                    present[arr[i-1]]=true;
                }
        }
        /*for (i=0;i<n;i++)
            out.println(i+" | "+present[i]+"   "+ans[i]);
        */
        i=0;
        j=0;
        while (i<n)
        {

            while (i<n&&ans[i]!=-1)
                i++;
            while (j<n&&present[j])
                j++;
            //out.println(i+"--------"+j);
            if (i<n)
            ans[i]=j;
            i++;
            j++;
        }
        for (i=0;i<n;i++)
            out.print(ans[i]+" ");

//================================================================================================================================
        out.flush();
        out.close();
    }

//================================================================================================================================
public static int[] sa(int n,InputReader sc)
{
    int inparr[]=new int[n];
    for (int i=0;i<n;i++)
        inparr[i]=sc.nextInt();
    return inparr;
}

    public static long gcd(long a,long b){
        return (a%b==0l)?b:gcd(b,a%b);
    }
    private static long lcm(long a, long b)
    {
        return a * (b / gcd(a, b));
    }
    public int egcd(int a, int b) {
        if (a == 0)
            return b;

        while (b != 0) {
            if (a > b)
                a = a - b;
            else
                b = b - a;
        }

        return a;
    }



    public int countChar(String str, char c)
    {
        int count = 0;
        for(int i=0; i < str.length(); i++)
        {    if(str.charAt(i) == c)
            count++;
        }
        return count;
    }
    static int binSearch(Integer[] inparr, int number){
        int left=0,right=inparr.length-1,mid=(left+right)/2,ind=0;
        while(left<=right){
            if(inparr[mid]<=number){
                ind=mid+1;
                left=mid+1;
            }
            else
                right=mid-1;
            mid=(left+right)/2;
        }
        return ind;
    }
    static int binSearch(int[] inparr, int number){
        int left=0,right=inparr.length-1,mid=(left+right)/2,ind=0;
        while(left<=right){
            if(inparr[mid]<=number){
                ind=mid+1;
                left=mid+1;
            }
            else
                right=mid-1;
            mid=(left+right)/2;
        }
        return ind;
    }
    static class Pair
    {
        int a,b;
        Pair(int aa,int bb)
        {
            a=aa;
            b=bb;
        }
        String get()
        {
            return a+" "+b;
        }
        String getrev()
        {
            return b+" "+a;
        }
    }

    static boolean isPrime(long n) {
        if(n < 2) return false;
        if(n == 2 || n == 3) return true;
        if(n%2 == 0 || n%3 == 0) return false;
        long sqrtN = (long)Math.sqrt(n)+1;
        for(long i = 6L; i <= sqrtN; i += 6) {
            if(n%(i-1) == 0 || n%(i+1) == 0) return false;
        }
        return true;
    }
    static long factorial(long n)
    {
        if (n == 0)
            return 1;
        return n*factorial(n-1);
    }
//================================================================================================================================

    static class InputReader
    {
        BufferedReader br;
        StringTokenizer st;

        public InputReader()
        {
            br = new BufferedReader(new
                    InputStreamReader(System.in));
        }

        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());
        }

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

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

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

    public static void main(String args[]) throws Exception {
        new Thread(null, new AA(),"Main",1<<27).start();
    }
}
