answer.code: In function ‘void add(int)’:
answer.code:18:5: error: ‘assert’ was not declared in this scope
   18 |     assert(ind != 0);
      |     ^~~~~~
answer.code:4:1: note: ‘assert’ is defined in header ‘<cassert>’; did you forget to ‘#include <cassert>’?
    3 | #include <map>
  +++ |+#include <cassert>
    4 | using namespace std;
answer.code: In function ‘int32_t main()’:
answer.code:84:9: error: ‘sort’ was not declared in this scope; did you mean ‘short’?
   84 |         sort(begin(cmp), end(cmp));
      |         ^~~~
      |         short
answer.code:85:19: error: ‘unique’ was not declared in this scope
   85 |         cmp.erase(unique(begin(cmp), end(cmp)), end(cmp));
      |                   ^~~~~~