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.*;

public class D {

	public static Reader sc = new Reader();
	//public static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	static class Move{
		int a, b;
		public Move(int i, int j) {
			a=i;
			b=j;
		}
	}
	public static void main(String[] args) throws IOException {
		//BufferedReader br = new BufferedReader(new FileReader("input.in"));

		int t = sc.nextInt();
		while (t-- > 0) {
			int n = sc.nextInt();
			int[] a=  new int[n];
			for (int i = 0; i < n; i++) {
				a[i] = i+1;
			}
			boolean[] keep = new boolean[n];
			int max = n;
			int[] next = new int[n];
			while (max > 2) {
				int pmax = max;
				keep[max-1] = true;
				max = (int)Math.ceil(Math.sqrt(max));
				next[pmax-1] = max-1;
			}
			next[max-1] = 1;
			List<Move> moves = new ArrayList<Move>();
			for (int i = n-1; i >= 2; i--) {
				if (keep[i]) continue;
				moves.add(new Move(i+1,n));
				a[i] = 1;
			}
			int cmax = n-1;
			int prev = -1;
			while (cmax != 1) {
				prev = cmax;
				moves.add(new Move(cmax+1,next[cmax]+1));
				moves.add(new Move(cmax+1,next[cmax]+1));
				cmax = next[cmax];
			}
			if (prev != 1) {
				moves.add(new Move(cmax+1,prev+1));
			}
			
			out.println(moves.size());
			for (Move move: moves) {
				out.println(move.a + " " + move.b);
			}
//			for (int i = 0; i < n; i++) {
//				out.print((keep[i] ? "Y":"N") +" ");
//			}
//			out.println();
//			for (int i = 0; i < n; i++) {
//				out.print(a[i] + " ");
//			}
//			out.println();
		}

		out.close();
	}

	static long ceil(long a, long b) {
		return (a + b - 1) / b;
	}

	static long powMod(long base, long exp, long mod) {
		if (base == 0 || base == 1)
			return base;
		if (exp == 0)
			return 1;
		if (exp == 1)
			return base % mod;
		long R = powMod(base, exp / 2, mod) % mod;
		R *= R;
		R %= mod;
		if ((exp & 1) == 1) {
			return base * R % mod;
		} else
			return R % mod;
	}

	static long pow(long base, long exp) {
		if (base == 0 || base == 1)
			return base;
		if (exp == 0)
			return 1;
		if (exp == 1)
			return base;
		long R = pow(base, exp / 2);
		if ((exp & 1) == 1) {
			return R * R * base;
		} else
			return R * R;
	}

	static class Reader {
		final private int BUFFER_SIZE = 1 << 16;
		private DataInputStream din;
		private byte[] buffer;
		private int bufferPointer, bytesRead;

		public Reader() {
			din = new DataInputStream(System.in);
			buffer = new byte[BUFFER_SIZE];
			bufferPointer = bytesRead = 0;
		}

		public Reader(String file_name) throws IOException {
			din = new DataInputStream(new FileInputStream(file_name));
			buffer = new byte[BUFFER_SIZE];
			bufferPointer = bytesRead = 0;
		}

		public String readLine() throws IOException {
			byte[] buf = new byte[64]; // line length 
			int cnt = 0, c;
			while ((c = read()) != -1) {
				if (c == '\n') {
					break;
				}
				buf[cnt++] = (byte) c;
			}
			return new String(buf, 0, Integer.max(cnt - 1, 0));
		}

		public int nextInt() throws IOException {
			int ret = 0;
			byte c = read();
			while (c <= ' ')
				c = read();
			boolean neg = (c == '-');
			if (neg)
				c = read();
			do {
				ret = ret * 10 + c - '0';
			} while ((c = read()) >= '0' && c <= '9');

			if (neg)
				return -ret;
			return ret;
		}

		public long nextLong() throws IOException {
			long ret = 0;
			byte c = read();
			while (c <= ' ')
				c = read();
			boolean neg = (c == '-');
			if (neg)
				c = read();
			do {
				ret = ret * 10 + c - '0';
			} while ((c = read()) >= '0' && c <= '9');
			if (neg)
				return -ret;
			return ret;
		}

		public double nextDouble() throws IOException {
			double ret = 0, div = 1;
			byte c = read();
			while (c <= ' ')
				c = read();
			boolean neg = (c == '-');
			if (neg)
				c = read();

			do {
				ret = ret * 10 + c - '0';
			} while ((c = read()) >= '0' && c <= '9');

			if (c == '.') {
				while ((c = read()) >= '0' && c <= '9') {
					ret += (c - '0') / (div *= 10);
				}
			}

			if (neg)
				return -ret;
			return ret;
		}

		private void fillBuffer() throws IOException {
			bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE);
			if (bytesRead == -1)
				buffer[0] = -1;
		}

		private byte read() throws IOException {
			if (bufferPointer == bytesRead)
				fillBuffer();
			return buffer[bufferPointer++];
		}

		public void close() throws IOException {
			if (din == null)
				return;
			din.close();
		}
	}

	public static PrintWriter out = new PrintWriter(new BufferedOutputStream(System.out));
}