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 CPP):

Solution:
#pragma GCC target ("avx2")
// #pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")

#include <iostream>
#include <array>
#include <algorithm>
#include <vector>
#include <bitset>
#include <set>
#include <unordered_set>
#include <cmath>
#include <complex>
#include <deque>
#include <iterator>
#include <numeric>
#include <map>
#include <unordered_map>
#include <queue>
#include <stack>
#include <string>
#include <tuple>
#include <utility>
#include <limits>
#include <iomanip>
#include <functional>
#include <cassert>
// #include <atcoder/all>
using namespace std;

using ll=long long;
template<class T> using V = vector<T>;
template<class T, class U> using P = pair<T, U>;
using vll = V<ll>;
using vii = V<int>;
using vvll = V<vll>;
using vvii = V< V<int> >;
using PII = P<int, int>;
using PLL = P<ll, ll>;
#define RevREP(i,n,a) for(ll i=n;i>a;i--)  // (a,n]
#define REP(i,a,n) for(ll i=a;i<n;i++)  // [a,n)
#define rep(i, n) REP(i,0,n)
#define ALL(v) v.begin(),v.end()
#define eb emplace_back
#define pb push_back

template < class T > inline bool chmax(T& a, T b) {if (a < b) { a=b; return true; } return false; }
template < class T > inline bool chmin(T& a, T b) {if (a > b) { a=b; return true; } return false; }
template< class A, class B > ostream& operator <<(ostream& out, const P<A, B> &p) {
    return out << '(' << p.first << ", " << p.second << ')';
}
template< class A > ostream& operator <<(ostream& out, const V<A> &v) {
    out << '[';
    for (int i=0;i<int(v.size());i++) {
        if (i) out << ", ";
        out << v[i];
    }
    return out << ']';
}

const long long MOD = 1000000007;
const long long HIGHINF = (long long)1e18;
const int INF = (int)1e9;

void solve() {
    int n; cin >> n;
    V<PII> ans;
    REP(i, 3, n) {
        if (i == 8) continue;
        ans.eb(PII(i, n));
    }

    if (n <= 8) {
        int r = (n + 1) / 2;
        rep(i, r) ans.eb(PII(n, 2));
    } else {
        int tmpn = n;
        while (tmpn > 1) ans.eb(PII(n, 8)), tmpn = (tmpn + 7) / 8;
        rep(i, 3) ans.eb(PII(8, 2));
    }

    cout << ans.size() << '\n';
    rep(i, int(ans.size())) cout << ans[i].first << ' ' << ans[i].second << '\n';
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    int t; cin >> t;
    while (t-->0) {
        solve();
    }
    return 0;
}