// Complete the activityNotifications function below.
set<pair<int, int> > hi;
set<pair<int, int>, greater<pair<int, int> > > lo;
int szlo, szhi;
void balance() {
    szlo = lo.size(), szhi = hi.size();
    while (szhi - szlo > 1) {  //hi kommbe
        lo.insert(*hi.begin());
        hi.erase(hi.begin());
        szlo = lo.size(), szhi = hi.size();
    }
    while (szlo - szhi > 1) {  //lo kombe
        hi.insert(*lo.begin());
        lo.erase(lo.begin());
        szlo = lo.size(), szhi = hi.size();
    }
}
void delet(int val, int id) {
    auto it = lo.find(make_pair(val, id));
    if (it != lo.end())
        lo.erase(it);
    else {
        auto it = hi.find(make_pair(val, id));
        if (it != hi.end()) hi.erase(it);
    }
    balance();
}
void insert(int val, int id) {
    lo.insert(make_pair(val, id));
    balance();
}
int find_median() {
    int szlo = lo.size(), szhi = hi.size();
    if (szlo > szhi) {
        return lo.begin()->first * 2;
    } else if (szhi > szlo) {
        return hi.begin()->first * 2;
    } else {
        return lo.begin()->first + hi.begin()->first;
    }
}
int activityNotifications(vector<int> ex, int d) {
    int res = 0;
    for (int i = 0; i < d; i++) insert(ex[i], i);
    for (int i = d; i < ex.size(); i++) {
        int md = find_median();
        //cout << "median " << double(md / 2.0) << endl;
        if (ex[i] >= md) res++;
        insert(ex[i], i);
        delet(ex[i - d], i - d);
    }
    return res;
}