CF1810B Candies
Description
This problem is about candy. Initially, you only have $ 1 $ candy, and you want to have exactly $ n $ candies.
You can use the two following spells in any order at most $ 40 $ times in total.
- Assume you have $ x $ candies now. If you use the first spell, then $ x $ candies become $ 2x-1 $ candies.
- Assume you have $ x $ candies now. If you use the second spell, then $ x $ candies become $ 2x+1 $ candies.
Construct a sequence of spells, such that after using them in order, you will have exactly $ n $ candies, or determine it's impossible.
Input Format
Each test contains multiple test cases. The first line contains a single integer $ t $ ( $ 1 \le t \le 10^4 $ ) — the number of test cases. Their description follows.
Each test case contains one line with a single integer $ n $ ( $ 2 \le n \le 10^9 $ ) — the required final number of candies.
Output Format
For each test case, output the following.
If it's possible to eventually have $ n $ candies within $ 40 $ spells, in the first line print an integer $ m $ ( $ 1 \le m \le 40 $ ), representing the total number of spells you use.
In the second print $ m $ integers $ a_{1}, a_{2}, \ldots, a_{m} $ ( $ a_{i} $ is $ 1 $ or $ 2 $ ) separated by spaces, where $ a_{i} = 1 $ means that you use the first spell in the $ i $ -th step, while $ a_{i} = 2 $ means that you use the second spell in the $ i $ -th step.
Note that you do not have to minimize $ m $ , and if there are multiple solutions, you may output any one of them.
If it's impossible, output $ -1 $ in one line.
Explanation/Hint
For $ n=3 $ , you can just use the second spell once, and then have $ 2 \cdot 1 + 1 = 3 $ candies.
For $ n=7 $ , you can use the second spell twice. After the first step, you will have $ 3 $ candies. And after the second step, you will have $ 2 \cdot 3 + 1 = 7 $ candies.