Given an array of distinct integers A, return all possible subsets.

Note: The list should not contain any duplicate subsets.

Example

A: [1, 3, 2]
Subsets: [
    [],
    [1],
    [1, 2],
    [1, 2, 3],
    [1, 3],
    [2],
    [2, 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 2

Expected Output

2

5
4

2
2 4
4
8

1
1 2
1 2 3
1 3
2
2 3
3

Constraint

1 <= T <= 10

1 <= n <= 10

1 <= Ai <= 100