Problem: 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 ≠ y) and set a_x = \left⌈ (a_x)/(a_y) \right⌉ (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 ⋅ 10^5) — the length of array a.

It's guaranteed that the sum of n over test cases doesn't exceed 2 ⋅ 10^5.

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.

Example

Input


2
3
4


Output


2
3 2
3 2
3
3 4
4 2
4 2

Note

In the first test case, you have array a = [1, 2, 3]. For example, you can do the following: 

  1. choose 3, 2: a_3 = \left⌈ (a_3)/(a_2) \right⌉ = 2 and array a = [1, 2, 2]; 
  2. choose 3, 2: a_3 = \left⌈ 2/2 \right⌉ = 1 and array a = [1, 2, 1]. 

You've got array with 2 ones and 1 two in 2 steps.

In the second test case, a = [1, 2, 3, 4]. For example, you can do the following: 

  1. choose 3, 4: a_3 = \left⌈ 3/4 \right⌉ = 1 and array a = [1, 2, 1, 4]; 
  2. choose 4, 2: a_4 = \left⌈ 4/2 \right⌉ = 2 and array a = [1, 2, 1, 2]; 
  3. choose 4, 2: a_4 = \left⌈ 2/2 \right⌉ = 1 and array a = [1, 2, 1, 1]. 

Solution (in JAVA):

Solution:
import java.io.*;
import java.util.ArrayList;
import java.util.List;
import java.util.StringTokenizer;

public class D {

    private static BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
    private static BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(System.out));
    private static StringTokenizer st;

    public static void main(String[] args) throws IOException {
        st = new StringTokenizer(reader.readLine());
        int T = Integer.parseInt(st.nextToken());
        for (int t = 0; t < T; t++) {
            st = new StringTokenizer(reader.readLine());
            int n = Integer.parseInt(st.nextToken());
            List<long[]> result = new ArrayList<>();
            long biggest = n;
            for (long i = n - 1; i >= 3; i--) {
                if (i <= (biggest + i - 1) / i) {
                    result.add(new long[] {n, i});
                    biggest = (biggest + i - 1) / i;
                }
                result.add(new long[]{i, n});
            }
            while (biggest > 2) {
                result.add(new long[] {n, 2});
                biggest = (biggest + 1) / 2;
            }
            result.add(new long[]{2, n});
            writer.write(Integer.toString(result.size()));
            writer.newLine();
            for (long[] step : result) {
                writer.write(step[0] + " " + step[1]);
                writer.newLine();
            }
        }
        writer.flush();
    }

}