Language: C++

#include<bits/stdc++.h>
using namespace std;
#define int long long
signed main() {
    int N;
    cin >> N;
    vector<int>a(N);
    set<int,int>Set;
    int ans = 0;
    for(int i = 0; i < N; i++) {
        cin >> a[i];
        if(a[i]/400 >= 8) {
            ans++;
        }
        else {
            Set.insert(a[i]/400);
        }
    }
    cout << ans+Set.size() << endl;
}

Compiler output:
In file included from /usr/include/c++/14/map:62,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:152,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_tree.h: In instantiation of 'std::pair<std::_Rb_tree_node_base*, std::_Rb_tree_node_base*> std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::_M_get_insert_unique_pos(const key_type&) [with _Key = long long int; _Val = long long int; _KeyOfValue = std::_Identity<long long int>; _Compare = long long int; _Alloc = std::allocator<long long int>; key_type = long long int]':
/usr/include/c++/14/bits/stl_tree.h:2169:4:   required from 'std::pair<std::_Rb_tree_iterator<_Val>, bool> std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::_M_insert_unique(_Arg&&) [with _Arg = long long int; _Key = long long int; _Val = long long int; _KeyOfValue = std::_Identity<long long int>; _Compare = long long int; _Alloc = std::allocator<long long int>]'
 2169 |         = _M_get_insert_unique_pos(_KeyOfValue()(__v));
      |           ^~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_set.h:523:25:   required from 'std::pair<typename std::_Rb_tree<_Key, _Key, std::_Identity<_Tp>, _Compare, typename __gnu_cxx::__alloc_traits<_Alloc>::rebind<_Key>::other>::const_iterator, bool> std::set<_Key, _Compare, _Alloc>::insert(value_type&&) [with _Key = long long int; _Compare = long long int; _Alloc = std::allocator<long long int>; typename std::_Rb_tree<_Key, _Key, std::_Identity<_Tp>, _Compare, typename __gnu_cxx::__alloc_traits<_Alloc>::rebind<_Key>::other>::const_iterator = std::_Rb_tree<long long int, long long int, std::_Identity<long long int>, long long int, std::allocator<long long int> >::const_iterator; typename __gnu_cxx::__alloc_traits<_Alloc>::rebind<_Key>::other = std::allocator<long long int>; typename __gnu_cxx::__alloc_traits<_Alloc>::rebind<_Key> = __gnu_cxx::__alloc_traits<std::allocator<long long int>, long long int>::rebind<long long int>; typename _Alloc::value_type = long long int; value_type = long long int]'
  523 |           _M_t._M_insert_unique(std::move(__x));
      |           ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~
a.cc:16:23:   required from here
   16 |             Set.insert(a[i]/400);
      |             ~~~~~~~~~~^~~~~~~~~~
/usr/include/c++/14/bits/stl_tree.h:2116:42: error: expression cannot be used as a function
 2116 |           __comp = _M_impl._M_key_compare(__k, _S_key(__x));
      |                    ~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_tree.h:2127:33: error: expression cannot be used as a function
 2127 |       if (_M_impl._M_key_compare(_S_key(__j._M_node), __k))
      |           ~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_tree.h: In instantiation of 'std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::iterator std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::_M_insert_(_Base_ptr, _Base_ptr, _Arg&&, _NodeGen&) [with _Arg = long long int; _NodeGen = std::_Rb_tree<long long int, long long int, std::_Identity<long long int>, long long int, std::allocator<long long int> >::_Alloc_node; _Key = long long int; _Val = long long int; _KeyOfValue = std::_Identity<long long int>; _Compare = long long int; _Alloc = std::allocator<long long int>; iterator = std::_Rb_tree<long long int, long long int, std::_Identity<long long int>, long long int, std::allocator<long long int> >::iterator; _Base_ptr = std::_Rb_tree_node_base*]':
/usr/include/c++/14/bits/stl_tree.h:2174:26:   required from 'std::pair<std::_Rb_tree_iterator<_Val>, bool> std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::_M_insert_unique(_Arg&&) [with _Arg = long long int; _Key = long long int; _Val = long long int; _KeyOfValue = std::_Identity<long long int>; _Compare = long long int; _Alloc = std::allocator<long long int>]'
 2174 |           return _Res(_M_insert_(__res.first, __res.second,
      |                       ~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
 2175 |                                  _GLIBCXX_FORWARD(_Arg, __v), __an),
      |                                  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_set.h:523:25:   required from 'std::pair<typename std::_Rb_tree<_Key, _Key, std::_Identity<_Tp>, _Compare, typename __gnu_cxx::__alloc_traits<_Alloc>::rebind<_Key>::other>::const_iterator, bool> std::set<_Key, _Compare, _Alloc>::insert(value_type&&) [with _Key = long long int; _Compare = long long int; _Alloc = std::allocator<long long int>; typename std::_Rb_tree<_Key, _Key, std::_Identity<_Tp>, _Compare, typename __gnu_cxx::__alloc_traits<_Alloc>::rebind<_Key>::other>::const_iterator = std::_Rb_tree<long long int, long long int, std::_Identity<long long int>, long long int, std::allocator<long long int> >::const_iterator; typename __gnu_cxx::__alloc_traits<_Alloc>::rebind<_Key>::other = std::allocator<long long int>; typename __gnu_cxx::__alloc_traits<_Alloc>::rebind<_Key> = __gnu_cxx::__alloc_traits<std::allocator<long long int>, long long int>::rebind<long long int>; typename _Alloc::value_type = long long int; value_type = long long int]'
  523 |           _M_t._M_insert_unique(std::move(__x));
      |           ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~
a.cc:16:23:   required from here
   16 |             Set.insert(a[i]/400);
      |             ~~~~~~~~~~^~~~~~~~~~
/usr/include/c++/14/bits/stl_tree.h:1824:56: error: expression cannot be used as a function
 1824 |                               || _M_impl._M_key_compare(_KeyOfValue()(__v),
      |                                  ~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~
 1825 |                                                         _S_key(__p)));
      |                                                         ~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_tree.h: In instantiation of 'static const _Key& std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::_S_key(_Const_Link_type) [with _Key = long long int; _Val = long long int; _KeyOfValue = std::_Identity<long long int>; _Compare = long long int; _Alloc = std::allocator<long long int>; _Const_Link_type = const std::_Rb_tree_node<long long int>*]':
/usr/include/c++/14/bits/stl_tree.h:2116:47:   required from 'std::pair<std::_Rb_tree_node_base*, std::_Rb_tree_node_base*> std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::_M_get_insert_unique_pos(const key_type&) [with _Key = long long int; _Val = long long int; _KeyOfValue = std::_Identity<long long int>; _Compare = long long int; _Alloc = std::allocator<long long int>; key_type = long long int]'
 2116 |           __comp = _M_impl._M_key_compare(__k, _S_key(__x));
      |                                                ~~~~~~^~~~~
/usr/include/c++/14/bits/stl_tree.h:2169:4:   required from 'std::pair<std::_Rb_tree_iterator<_Val>, bool> std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::_M_insert_unique(_Arg&&) [with _Arg = long long int; _Key = long long int; _Val = long long int; _KeyOfValue = std::_Identity<long long int>; _Compare = long long int; _Alloc = std::allocator<long long int>]'
 2169 |         = _M_get_insert_unique_pos(_KeyOfValue()(__v));
      |           ^~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_set.h:523:25:   required from 'std::pair<typename std::_Rb_tree<_Key, _Key, std::_Identity<_Tp>, _Compare, typename __gnu_cxx::__alloc_traits<_Alloc>::rebind<_Key>::other>::const_iterator, bool> std::set<_Key, _Compare, _Alloc>::insert(value_type&&) [with _Key = long long int; _Compare = long long int; _Alloc = std::allocator<long long int>; typename std::_Rb_tree<_Key, _Key, std::_Identity<_Tp>, _Compare, typename __gnu_cxx::__alloc_traits<_Alloc>::rebind<_Key>::other>::const_iterator = std::_Rb_tree<long long int, long long int, std::_Identity<long long int>, long long int, std::allocator<long long int> >::const_iterator; typename __gnu_cxx::__alloc_traits<_Alloc>::rebind<_Key>::other = std::allocator<long long int>; typename __gnu_cxx::__alloc_traits<_Alloc>::rebind<_Key> = __gnu_cxx::__alloc_traits<std::allocator<long long int>, long long int>::rebind<long long int>; typename _Alloc::value_type = long long int; value_type = long long int]'
  523 |           _M_t._M_insert_unique(std::move(__x));
      |           ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~
a.cc:16:23:   required from here
   16 |             Set.insert(a[i]/400);
      |             ~~~~~~~~~~^~~~~~~~~~
/usr/include/c++/14/bits/stl_tree.h:760:23: error: static assertion failed: comparison object must be invocable with two arguments of key type
  760 |         static_assert(__is_invocable<_Compare&, const _Key&, const _Key&>{},
      |                       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_tree.h:760:23: note: 'std::__is_invocable<long long int&, const long long int&, const long long int&>()' evaluates to false