You are an expert competitive programmer. You will be given a problem statement, test case constraints and example test inputs and outputs. Please reason step by step about the solution (that must respect memory and time limits), then provide a complete implementation in python3.

Your solution must read input from standard input (cin), write output to standard output (cout).
Do not include any debug prints or additional output.

Put your final solution within a single code block:
```python
<your code here>
```

Execution time limit: 1.0 seconds
Memory limit: 256.0 MB

# Problem
During Zhongkao examination, Reycloer met an interesting problem, but he cannot come up with a solution immediately. Time is running out! Please help him.

Initially, you are given an array $$$a$$$ consisting of $$$n \ge 2$$$ integers, and you want to change all elements in it to $$$0$$$.

In one operation, you select two indices $$$l$$$ and $$$r$$$ ($$$1\le l\le r\le n$$$) and do the following:

- Let $$$s=a_l\oplus a_{l+1}\oplus \ldots \oplus a_r$$$, where $$$\oplus$$$ denotes the bitwise XOR operation;
- Then, for all $$$l\le i\le r$$$, replace $$$a_i$$$ with $$$s$$$.

You can use the operation above in any order at most $$$8$$$ times in total.

Find a sequence of operations, such that after performing the operations in order, all elements in $$$a$$$ are equal to $$$0$$$. It can be proven that the solution always exists.

## Input Format
The first line of input contains a single integer $$$t$$$ ($$$1\le t\le 500$$$) — the number of test cases. The description of test cases follows.

The first line of each test case contains a single integer $$$n$$$ ($$$2\le n\le 100$$$) — the length of the array $$$a$$$.

The second line of each test case contains $$$n$$$ integers $$$a_1,a_2,\ldots,a_n$$$ ($$$0\le a_i\le 100$$$) — the elements of the array $$$a$$$.

## Output Format
For each test case, in the first line output a single integer $$$k$$$ ($$$0\le k\le 8$$$) — the number of operations you use.

Then print $$$k$$$ lines, in the $$$i$$$-th line output two integers $$$l_i$$$ and $$$r_i$$$ ($$$1\le l_i\le r_i\le n$$$) representing that you select $$$l_i$$$ and $$$r_i$$$ in the $$$i$$$-th operation.

Note that you do not have to minimize $$$k$$$. If there are multiple solutions, you may output any of them.

## Examples
```input
6
4
1 2 3 0
8
3 1 4 1 5 9 2 6
6
1 5 4 1 4 7
5
0 0 0 0 0
7
1 1 9 9 0 1 8
3
100 100 0
```
```output
1
1 4
2
4 7
1 8
6
1 2
3 4
5 6
1 3
4 6
1 6
0
4
1 2
6 7
3 4
6 7
1
1 2
```

## Note
In the first test case, since $$$1\oplus2\oplus3\oplus0=0$$$, after performing the operation on segment $$$[1,4]$$$, all the elements in the array are equal to $$$0$$$.

In the second test case, after the first operation, the array becomes equal to $$$[3,1,4,15,15,15,15,6]$$$, after the second operation, the array becomes equal to $$$[0,0,0,0,0,0,0,0]$$$.

In the third test case:

Operation$$$a$$$ before$$$a$$$ after$$$1$$$$$$[\underline{1,5},4,1,4,7]$$$$$$\rightarrow$$$$$$[4,4,4,1,4,7]$$$$$$2$$$$$$[4,4,\underline{4,1},4,7]$$$$$$\rightarrow$$$$$$[4,4,5,5,4,7]$$$$$$3$$$$$$[4,4,5,5,\underline{4,7}]$$$$$$\rightarrow$$$$$$[4,4,5,5,3,3]$$$$$$4$$$$$$[\underline{4,4,5},5,3,3]$$$$$$\rightarrow$$$$$$[5,5,5,5,3,3]$$$$$$5$$$$$$[5,5,5,\underline{5,3,3}]$$$$$$\rightarrow$$$$$$[5,5,5,5,5,5]$$$$$$6$$$$$$[\underline{5,5,5,5,5,5}]$$$$$$\rightarrow$$$$$$[0,0,0,0,0,0]$$$

In the fourth test case, the initial array contains only $$$0$$$, so we do not need to perform any operations with it.

Now solve the problem and return the code.