void solve(){

   ll n; cin >> n;
   vector < ll > v;
   for (int i = 1; i <= n; i++)  v.push_back(i);


   set < ll > st (all(v));

   for (int i = 1; i < sz(v) ; i += 2)
   {


        cout << v[i] << " ";
        st.erase(v[i]);


        if(i == sz(v) - 2 and st.find(v[i]) == st.end()) v.assign(all(st)) , i = -2;

        if(i == sz(v) - 1  and st.find(v[i]) == st.end()) v.assign(all(st)) , i = -1;


      }

      cout(st);



}