Language: C++

#include <bits/stdc++.h>
#define REP(i,n) for (int i=0;i<(n);i++)
#define FOR(i,s,e) for (int i=s;i<(e);i++)
#define All(v) (v).begin(),(v).end()
#define mp(a,b) make_pair(a,b)
#define pb(a) push_back(a)
#define chmax(x, y) x = max(x, y)
#define chmin(x, y) x = min(x, y)
#define int long long
using namespace std;
typedef long long llint;
typedef pair<int, int> P;
const int MOD = (int)1e9 + 7;
const int INF = (int)1e18 * 5;

signed main(){
    cin.tie(0);
    ios::sync_with_stdio(false);

    int N, M;
    cin >> N;
    multiset<string> s, t;
    set<string> ls;
    REP(i, N){
        string st;
        cin >> st;
        s.insert(st);
        ls.insert(st);
    }
    cin >> M;
    REP(i, N){
        string st;
        cin >> st;
        t.insert(st);
        ls.insert(st);
    }
    int ans = 0;
    for(auto x: ls){
        chmax(ans, (int)s.count(x)-t.count(x));
    }
    cout << ans << "\n";
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:7:28: error: no matching function for call to 'max(long long int&, long long unsigned int)'
    7 | #define chmax(x, y) x = max(x, y)
      |                         ~~~^~~~~~
a.cc:39:9: note: in expansion of macro 'chmax'
   39 |         chmax(ans, (int)s.count(x)-t.count(x));
      |         ^~~~~
In file included from /usr/include/c++/14/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:51,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_algobase.h:257:5: note: candidate: 'template<class _Tp> constexpr const _Tp& std::max(const _Tp&, const _Tp&)'
  257 |     max(const _Tp& __a, const _Tp& __b)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:257:5: note:   template argument deduction/substitution failed:
a.cc:7:28: note:   deduced conflicting types for parameter 'const _Tp' ('long long int' and 'long long unsigned int')
    7 | #define chmax(x, y) x = max(x, y)
      |                         ~~~^~~~~~
a.cc:39:9: note: in expansion of macro 'chmax'
   39 |         chmax(ans, (int)s.count(x)-t.count(x));
      |         ^~~~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note: candidate: 'template<class _Tp, class _Compare> constexpr const _Tp& std::max(const _Tp&, const _Tp&, _Compare)'
  303 |     max(const _Tp& __a, const _Tp& __b, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note:   candidate expects 3 arguments, 2 provided
In file included from /usr/include/c++/14/algorithm:61:
/usr/include/c++/14/bits/stl_algo.h:5706:5: note: candidate: 'template<class _Tp> constexpr _Tp std::max(initializer_list<_Tp>)'
 5706 |     max(initializer_list<_Tp> __l)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5706:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_algo.h:5716:5: note: candidate: 'template<class _Tp, class _Compare> constexpr _Tp std::max(initializer_list<_Tp>, _Compare)'
 5716 |     max(initializer_list<_Tp> __l, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5716:5: note:   template argument deduction/substitution failed:
a.cc:7:28: note:   mismatched types 'std::initializer_list<_Tp>' and 'long long int'
    7 | #define chmax(x, y) x = max(x, y)
      |                         ~~~^~~~~~
a.cc:39:9: note: in expansion of macro 'chmax'
   39 |         chmax(ans, (int)s.count(x)-t.count(x));
      |         ^~~~~