Given an array of integers A, return all possible subsets. The array might contain duplicates.

Note: The list should not contain any duplicate subsets.

Example

A: [1, 3, 3]
Subsets: [
    [],
    [1],
    [1, 3],
    [1, 3, 3],
    [3],
    [3, 3]
]

Testing

Input Format

The first line contains an integer ‘T’, denoting the number of test cases.

For each test case, the input has two lines.

• An integer ‘n’ denoting the length of the array A.
• n space-separated unique integers denoting the elements of the array A.

Output Format

For each test case, the output has the following lines:

• The first line contains an integer ‘m’ denoting the total no of subsets.
• The next m line contains space-separated integers denoting elements in that particular subset.

Sample Input

3
1
5
2
2 4
3
1 3 3

Expected Output

2

5
4

2
2 4
4
6

1
1 3
1 3 3
3
3 3

Constraint

1 <= T <= 10

1 <= n <= 10

1 <= Ai <= 100