coursera

#include <iostream>
#include <vector>
#include<string>

using namespace std;

int main() {
    int operation;
    int people;
    vector<bool> silent;
    int sum=0;
    cin >> operation;

    for (int i = 0; i < operation; i++)
    {
        string check;
        cin >> check;
        if (check=="COME"){
            cin >> people;
            if (people>0)
            {
                silent.assign(silent.size()+people,false);
            }
            else
            {
                silent.resize(silent.size() + people);
            }
        }
        else if(check=="WORRY")
        {
            cin >> people;
            silent[people] = true;
        }
        else if (check == "QUIET")
        {
            cin >> people;
            silent[people] = false;
        }
        else if (check == "WORRY_COUNT")
        {
            for (auto k : silent) {
                if (k==true)
                {
                    sum++;
                }
            }
            cout << sum<<endl;
        }
        else
        {
            cout << " " << endl;
        }
    }

    return 0;
}