### B. Restore the Permutation by Merger

A permutation of length n is a sequence of integers from 1 to n of length n containing each number exactly once. For example, [1], [4,3,5,1,2], [3,2,1] are permutations, and [1,1], [0,1], [2,2,1,4] are not.

There was a permutation p[1…n]. It was merged with itself. In other words, let's take two instances of p and insert elements of the second p into the first maintaining relative order of elements. The result is a sequence of the length 2n.

For example, if p=[3,1,2] some possible results are: [3,1,2,3,1,2], [3,3,1,1,2,2], [3,1,3,1,2,2]. The following sequences are not possible results of a merging: [1,3,2,1,2,3], [3,1,2,3,2,1], [3,3,1,2,2,1].

For example, if p=[2,1] the possible results are: [2,2,1,1], [2,1,2,1]. The following sequences are not possible results of a merging: [1,1,2,2], [2,1,1,2], [1,2,2,1].

Your task is to restore the permutation by the given resulting sequence . It is guaranteed that the answer exists and is unique.

You have to answer independent test cases.

The first line of the input contains one integer () — the number of test cases. Then test cases follow.

The first line of the test case contains one integer () — the length of permutation. The second line of the test case contains integers (), where is the -th element of . It is guaranteed that the array represents the result of merging of some permutation with the same permutation .

For each test case, print the answer: integers (), representing the initial permutation. It is guaranteed that the answer exists and is unique.

5 2 1 1 2 2 4 1 3 1 4 3 4 2 2 5 1 2 1 2 3 4 3 5 4 5 3 1 2 3 1 2 3 4 2 3 2 4 1 3 4 1

1 2 1 3 4 2 1 2 3 4 5 1 2 3 2 3 4 1

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