B"You have an array a_1, a_2, ... , a_n where a_i = i . In one step, you can choose two indices x and y ( x neq y ) and set a_x = <= ft lceil frac{a_x}{a_y} right rceil (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. 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 cdot 10^5 ) -- the length of array a . It's guaranteed that the sum of n over test cases doesn't exceed 2 cdot 10^5 . 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 neq 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. In the first test case, you have array a = [1, 2, 3] . For example, you can do the following: In the second test case, a = [1, 2, 3, 4] . For example, you can do the following: "...