#include <bits/stdc++.h>

using namespace std;

class city {
  public:
    const int latitude;
    const int longitude;
    const int points;
    const int height;
    int total_points;
    city(int lat, int lon, int p, int h): latitude (lat), longitude (lon), points (p), height (h) {};
};

multimap <int, city*> cities;

multimap <int, city*> cities_by_points;

int x;
int y;

int set_total_points (std::multimap<int, city*>::iterator pointer) {
    int best_points = 0;
    for (std::multimap<int, city*>::reverse_iterator iter = cities_by_points.rbegin(); iter != cities_by_points.rend(); ++iter) {
        if (abs(iter->second->latitude - pointer->second->latitude) > x) continue;
        if (abs(iter->second->longitude - pointer->second->longitude) > y) continue;
        if (iter->second->height == pointer->first) continue;
        if (iter->second->total_points <= best_points) continue;
        best_points = iter->second->total_points;
        break;
    }
    int result = best_points + pointer->second->points;
    pointer->second->total_points = result;
    cities_by_points.insert(make_pair(result, pointer->second));
    return pointer->second->total_points;
}


int main(){
    int n;
    cin >> n >> x >> y;
    for(int a0 = 0; a0 < n; a0++){
        int latitude;
        int longitude;
        int height;
        int points;
        cin >> latitude >> longitude >> height >> points;
        cities.insert(make_pair(height, new city(latitude, longitude, points, height)));
    }
    int best_total;
    for (std::multimap<int, city*>::iterator iter = cities.begin(); iter != cities.end(); ++iter) {
        int current_total = set_total_points(iter);
        if (current_total > best_total) best_total = current_total;
    }
    cout << best_total;
    return 0;
}