func_code_string: #include <bits/stdc++.h>   #define ll long long int   #define vi vector<int>   #define vll vector<long long int>   #define MAX(a, b) ((a) > (b) ? (a) : (b))   #define MIN(a, b) ((a) < (b) ? (a) : (b))   #define ABS(x) ((x) < 0 ? -(x) : (x))   #define setpr(x, y) cout << fixed << setprecision(x) << y   #define tr(x) cout << (#x) <<   =   << (x) <<   n ;   using namespace std;   void solver(void);   ll MOD = 1e9 + 7;   double pi = 2 * acos(0.0);   //vector<vector<ll>> mat( n , vector<ll> (m, 0));      int main()   {       cin.tie(NULL);       ios_base::sync_with_stdio(false);       int t;       cin >> t;       while (t--)           solver();   }   void solver(void)   {       //input       ll n;       cin >> n;       vll v(n);       for (ll i = 0; i < n; i++)       {           v[i] = i + 1;       }       if (n % 2 == 0)       {              for (ll i = 0; i < n - 1; i = i + 2)           {               swap(v[i], v[i + 1]);           }       }       else       {           for (ll i = 0; i <= n - 3; i = i + 2)           {               swap(v[i], v[i + 1]);           }           swap(v[n - 2], v[n - 1]);       }       for (ll i = 0; i < n; i++)       {           cout << v[i] <<    ;       }       cout <<   n ;   }   