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.
//    A Computer is Like a mischievous genie.
//    It will give you exactly what you ask for,
//    but not always what you want
//    A code by Rahul Verma


import java.util.*;
import java.io.*;


public class Main {


    static class Clock {

        protected long start, stop;

        public void start() {
            start = System.currentTimeMillis();
        }

        public void stop() {
            stop = System.currentTimeMillis();
        }

        public String getTime() {
            return ((stop - start) + " ms");
        }
    }


    public static PrintWriter out = new PrintWriter(new BufferedOutputStream(System.out));

    static class FastReader {

        BufferedReader br;
        StringTokenizer st;

        public FastReader() {
            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[] nextSArray() {
            String sr[] = null;
            try {
                sr = br.readLine().trim().split(" ");
            } catch (IOException e) {
                e.printStackTrace();
            }
            return sr;
        }

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

            return str;
        }
    }


    static long powmodulo(long a, long p) {
        if (p == 0) {
            return 1 % mod;
        }
        if (p == 1) {
            return a % mod;
        }
        long ans = 1;
        while (p > 0) {
            if ((p & 1) > 0) {
                ans = (ans * a) % mod;
            }
            a = (a * a) % mod;
            p = p >> 1;
        }
        return ans % mod;
    }


    static long mod = 1000000007;

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

    static long fast_powerNumbers(long a, long n) {
        if (n == 1) {
            return a;
        }
        long ans = fast_powerNumbers(a, n / 2);
        if (n % 2 == 0) {
            return (ans * ans);
        } else {
            return ((ans * ans) * (a));
        }
    }




    static int arr[];

    static void seive(int n) {
        arr = new int[n + 1];
        arr[0] = arr[1] = 1;
        for (int i = 4; i <= n; i = i + 2) {
            arr[i] = 1;
        }
        for (int i = 3; i * i <= n; i = i + 2) {
            if (arr[i] == 0) {
                for (int j = i * i; j <= n; j = j + i) {
                    arr[j] = 1;
                }

            }
        }
    }
    public static void main(String[] args) throws Exception {
        FastReader sc = new FastReader();

        Clock clock = new Clock();
        clock.start();
      int n=sc.nextInt();
      int arr[]=new int[n];
      int brr[]=new int[n];

        int max=n;
        HashSet<Integer>set=new HashSet<>();
        boolean ans=true;
        for (int i = 0; i <n ; i++) {
            arr[i] = sc.nextInt();
            if (arr[i] > i + 1)
            {
                ans=false;
            }


        }
        set.add(arr[n-1]);
        if(!ans)
        {
            System.out.println(-1);
            return;
        }

       // System.out.println(pq);
        for (int i = n-1; i >0 ; --i) {
            int ele = arr[i-1];
            if(!set.contains(ele))
            {
                set.add(ele);
                brr[i]=ele;
            }
            else {
                while(set.contains(max))
                    --max;
                int x = max;
                if (x < ele)
                {
                    System.out.println(-1);
                    return;
                }
                brr[i]=x;
                set.add(max);

            }
        }
        while(set.contains(max))
            --max;
        brr[0] = max;

        for (int i = 0; i <n ; i++) {
            out.print(brr[i]+" ");
        }
        out.println();
        out.close();


    }


}


 class Pair implements Comparator<Pair> {

    int a;
    int b;

    Pair(int a, int b) {
        this.a = a;
        this.b = b;
    }

     @Override
     public int compare(Pair o1, Pair o2) {
         return 0;
     }
 }


// out.println(al.toString().replaceAll("[\\[|\\]|,]",""));


