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:

// Problem: D. Ceil Divisions
// Contest: Codeforces - Educational Codeforces Round 101 (Rated for Div. 2)
// URL: https://codeforces.com/contest/1469/problem/D
// Memory Limit: 256 MB
// Time Limit: 2000 ms
// Powered by CP Editor (https://github.com/cpeditor/cpeditor)

import java.io.*;
import java.util.*;

public class Main {
    private static PrintWriter pw = new PrintWriter(System.out);
    private static InputReader sc = new InputReader();
    private static final int intmax = Integer.MAX_VALUE, intmin = Integer.MIN_VALUE;

    static class InputReader{
        private static BufferedReader r = new BufferedReader(new InputStreamReader(System.in));
        private static StringTokenizer tk;

        private void next()throws IOException{
            while(tk == null || !tk.hasMoreTokens())   
                tk = new StringTokenizer(r.readLine());
        }

        private int nextInt()throws IOException{
            next();
            return Integer.parseInt(tk.nextToken());
        }

        private long nextLong()throws IOException{
            next();
            return Long.parseLong(tk.nextToken());
        }

        private String readString()throws IOException{
            next();
            return tk.nextToken();
        }

        private double nextDouble()throws IOException{
            next();
            return Double.parseDouble(tk.nextToken());
        }

        private int[] intArray(int n)throws IOException{
            next();
            int arr[] = new int[n];

            for(int i=0; i<n; i++)
                arr[i] = nextInt();

            return arr;
        }

        private long[] longArray(int n)throws IOException{
            next();
            long arr[] = new long[n];

            for(int i=0; i<n; i++)
                arr[i] = nextLong();

            return arr;
        }
    }

    public static void main(String args[])throws IOException{
        int t = sc.nextInt();
        // int t = 1;
        while(t-->0)    solve();
        pw.flush();
        pw.close();
    }

    private static void solve()throws IOException{
		int n = sc.nextInt(), ptr = n;
		
		ArrayList<int[]> ans = new ArrayList<>();
		
		while(ptr > 2){
			int new_ptr = (int)Math.ceil(Math.sqrt((double)ptr));
			
			for(int i = new_ptr + 1; i < ptr; i++)
				ans.add(new int[]{i, ptr});
				
			ans.add(new int[]{ptr, new_ptr});
			ans.add(new int[]{ptr, new_ptr});
			
			ptr = new_ptr;
		}
		
		pw.println(ans.size());
		
		for(int[] pair: ans)
			pw.println(+pair[0]+" "+pair[1]);
    }
}