## Algorithm

B. Restore the Permutation by Merger
time limit per test
1 second
memory limit per test
256 megabytes
input
standard input
output
standard output

A permutation of length n is a sequence of integers from 11 to n of length n containing each number exactly once. For example, [1][1][4,3,5,1,2][4,3,5,1,2][3,2,1][3,2,1] are permutations, and [1,1][1,1][0,1][0,1][2,2,1,4][2,2,1,4] are not.

There was a permutation p[1n]�[1…�]. 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 2n2�.

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

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

Input

The first line of the input contains one integer t (1t4001≤�≤400) — the number of test cases. Then t test cases follow.

The first line of the test case contains one integer n (1n501≤�≤50) — the length of permutation. The second line of the test case contains 2n2� integers a1,a2,,a2n�1,�2,…,�2� (1ain1≤��≤�), where ai�� 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.

Output

For each test case, print the answer: n integers p1,p2,,pn�1,�2,…,�� (1pin1≤��≤�), representing the initial permutation. It is guaranteed that the answer exists and is unique.

Example
input
Copy
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

output
Copy
1 2
1 3 4 2
1 2 3 4 5
1 2 3
2 3 4 1


## Code Examples

### #1 Code Example with C++ Programming

Code - C++ Programming

#include<bits/stdc++.h>
using namespace std;

int main(){
int t;
cin>>t;
while(t--){
int n;
cin>>n;
int arr[n];
map<int, bool> inp;
int x, k = 0;
for(int i = 0; i < 2*n; i++){
cin>>x;
if(!inp[x]){
arr[k] = x;
inp[x] = true;
k++;
}
}
for(int i = 0; i < n; i++){
cout<<arr[i]<<" ";
}
cout<<endl;
}
}
Copy The Code &

Input

cmd
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

Output

cmd
1 2
1 3 4 2
1 2 3 4 5
1 2 3
2 3 4 1
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## Demonstration

Codeforcess solution 1385-B B. Restore the Permutation by Merger ,C++, Java, Js and Python,1385-B,Codeforcess solution