answer.code: In function ‘void add(int, std::string&, int)’:
answer.code:20:20: error: ‘struct node’ has no member named ‘nxt’
   20 |         if (!tr[p].nxt[v]) tr[p].nxt[v] = ++cnt;
      |                    ^~~
answer.code:20:34: error: ‘struct node’ has no member named ‘nxt’
   20 |         if (!tr[p].nxt[v]) tr[p].nxt[v] = ++cnt;
      |                                  ^~~
answer.code:21:23: error: ‘struct node’ has no member named ‘nxt’
   21 |         insert (tr[p].nxt[v], s, d + 1);
      |                       ^~~
answer.code:21:9: error: ‘insert’ was not declared in this scope; did you mean ‘assert’?
   21 |         insert (tr[p].nxt[v], s, d + 1);
      |         ^~~~~~
      |         assert