CF1385B 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 \dots 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 $ p $ by the given resulting sequence $ a $ . It is guaranteed that the answer exists and is unique. You have to answer $ t $ independent test cases.

The first line of the input contains one integer $ t $ ( $ 1 \le t \le 400 $ ) — the number of test cases. Then $ t $ test cases follow. The first line of the test case contains one integer $ n $ ( $ 1 \le n \le 50 $ ) — the length of permutation. The second line of the test case contains $ 2n $ integers $ a_1, a_2, \dots, a_{2n} $ ( $ 1 \le a_i \le n $ ), where $ a_i $ is the $ i $ -th element of $ a $ . It is guaranteed that the array $ a $ represents the result of merging of some permutation $ p $ with the same permutation $ p $ .

For each test case, print the answer: $ n $ integers $ p_1, p_2, \dots, p_n $ ( $ 1 \le p_i \le n $ ), representing the initial permutation. It is guaranteed that the answer exists and is unique.