#include <bits/stdc++.h>   using namespace std;   void solve() {     int n;     cin >> n;     priority_queue<int> pq{};     for (int i{1}; i <= n; ++i) pq.push(i);     vector<pair<int, int>> ans{};     for (int i{0}; i < n - 1; ++i) {       int mx1{pq.top()};       pq.pop();       int mx2{pq.top()};       pq.pop();       ans.push_back({mx1, mx2});       pq.push((mx1 + mx2 + 1) / 2);     }     cout << pq.top() <<   n ;     for (auto& x : ans) cout << x.first <<     << x.second <<   n ;   }   void solve2() {     int n;     cin >> n;     cout <<  2 n ;     cout << n <<     << n - 1 <<   n ;     for (int i{n}; i >= 3; --i) cout << i <<     << i - 2 <<   n ;   }   int main() {     ios_base::sync_with_stdio(false);     cin.tie(nullptr);     int t;     cin >> t;     while (t--) solve2();     return 0;   }   