func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     ios_base::sync_with_stdio(0);     cin.tie(NULL);     int n;     cin >> n;     vector<char> c(n);     vector<int> id(n);     map<int, bool> state, exist;     for (int i = 0; i < n; i++) cin >> c[i] >> id[i];     for (int i = 0; i < n; i++) {       if (c[i] ==  + )         exist[id[i]] = true;       else {         if (exist[id[i]])           exist[id[i]] = false;         else           state[id[i]] = true;       }     }     int ans = state.size();     for (int i = 0; i < n; i++) {       if (c[i] ==  + )         state[id[i]] = true;       else {         state.erase(id[i]);       }       ans = max(ans, int(state.size()));     }     cout << ans;     return 0;   }   