can choose two indices x and y (x≠y) and set ax=⌈axay⌉ (ceiling function). Your goal is to make array a consist of n−1 ones and 1 two in no more than n+5 steps. Note that you don't have to minimize the number of steps. Input
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you can choose two indices x and y (x≠y) and set ax=⌈axay⌉ (ceiling function).
Your goal is to make array a consist of n−1 ones and 1 two in no more than n+5 steps. Note that you don't have to minimize the number of steps.
Input
The first line contains a single integer t (1≤t≤1000) — the number of test cases.
The first and only line of each test case contains the single integer n (3≤n≤2⋅105) — the length of array a.
It's guaranteed that the sum of n over test cases doesn't exceed 2⋅105.
Output
For each test case, print the sequence of operations that will make a as n−1 ones and 1 two in the following format: firstly, print one integer m (m≤n+5) — the number of operations; next print m pairs of integers x and y (1≤x,y≤n; x≠y) (x may be greater or less than y) — the indices of the corresponding operation.
It can be proven that for the given constraints it's always possible to find a correct sequence of operations.
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