Permutation $p$ is a sequence of integers $p=[p_1, p_2, \dots, p_n]$, consisting of $n$ distinct (unique) positive integers between $1$ and $n$, inclusive. For example, the following sequences are permutations: $[3, 4, 1, 2]$, $[1]$, $[1, 2]$. The following sequences are not permutations: $[0]$, $[1, 2, 1]$, $[2, 3]$, $[0, 1, 2]$.
The important key is in the locked box that you need to open. To open the box you need to enter secret code. Secret code is a permutation $p$ of length $n$. 
You don't know this permutation, you only know the array $q$ of prefix maximums of this permutation. Formally:  $q_1=p_1$,  $q_2=\max(p_1, p_2)$,  $q_3=\max(p_1, p_2,p_3)$,  ...  $q_n=\max(p_1, p_2,\dots,p_n)$. 
You want to construct any possible suitable permutation (i.e. any such permutation, that calculated $q$ for this permutation is equal to the given array).
-----Input-----
The first line contains integer number $t$ ($1 \le t \le 10^4$) — the number of test cases in the input. Then $t$ test cases follow.
The first line of a test case contains one integer $n$ $(1 \le n \le 10^{5})$ — the number of elements in the secret code permutation $p$.
The second line of a test case contains $n$ integers $q_1, q_2, \dots, q_n$ $(1 \le q_i \le n)$ — elements of the array $q$ for secret permutation. It is guaranteed that $q_i \le q_{i+1}$ for all $i$ ($1 \le i < n$).
The sum of all values $n$ over all the test cases in the input doesn't exceed $10^5$.
-----Output-----
For each test case, print:  If it's impossible to find such a permutation $p$, print "-1" (without quotes).  Otherwise, print $n$ distinct integers $p_1, p_2, \dots, p_n$ ($1 \le p_i \le n$). If there are multiple possible answers, you can print any of them. 
-----Example-----
Input
4
5
1 3 4 5 5
4
1 1 3 4
2
2 2
1
1
Output
1 3 4 5 2 
-1
2 1 
1 
-----Note-----
In the first test case of the example answer $[1,3,4,5,2]$ is the only possible answer:  $q_{1} = p_{1} = 1$;  $q_{2} = \max(p_{1}, p_{2}) = 3$;  $q_{3} = \max(p_{1}, p_{2}, p_{3}) = 4$;  $q_{4} = \max(p_{1}, p_{2}, p_{3}, p_{4}) = 5$;  $q_{5} = \max(p_{1}, p_{2}, p_{3}, p_{4}, p_{5}) = 5$. 
It can be proved that there are no answers for the second test case of the example.
for __ in range(int(input())):
    n = int(input())
    ar1 = list(map(int, input().split()))
    ar = ar1.copy()
    lol = set()
    for j in range(1, n + 1):
        lol.add(j)
    lol.discard(ar[0])
    for i in range(1, n):
        if ar1[i] > ar1[i - 1]:
            lol.discard(ar1[i])
        else:
            ar[i] = 0
    kek = list(lol)
    kek.sort()
    num = 0
    flag = 0
    for j in range(n):
        if ar[j] == 0:
            ar[j] = kek[num]
            num += 1
        if ar[j] > ar1[j]:
            flag = 1
    if flag == 1:
        print(-1)
    else:
        print(*ar)

for __ in range(int(input())):
    n = int(input())
    ar1 = list(map(int, input().split()))
    ar = ar1.copy()
    lol = set()
    for j in range(1, n + 1):
        lol.add(j)
    lol.discard(ar[0])
    for i in range(1, n):
        if ar1[i] > ar1[i - 1]:
            lol.discard(ar1[i])
        else:
            ar[i] = 0
    kek = list(lol)
    kek.sort()
    num = 0
    flag = 0
    for j in range(n):
        if ar[j] == 0:
            ar[j] = kek[num]
            num += 1
        if ar[j] > ar1[j]:
            flag = 1
    if flag == 1:
        print(-1)
    else:
        print(*ar)
