import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {
    static class City implements Comparable<City>{
        int lat;
        int lon;
        int height;
        int points;
        public City(int lat, int lon, int height, int points){
            this.lat=lat;
            this.lon = lon;
            this.height = height;
            this.points = points;
        }
        public int compareTo(City c){
            return this.height-c.height;
        }        
        
    }
    
    static long getMaxSum(ArrayList<City> cities, int n, int x, int y){
        Collections.sort(cities);
        long maxSum = 0;
        long sum = 0;
        City prev = null;
        for(int k=0;k<cities.size();k++){
            sum=0;
            for(int i=k;k<cities.size();k++){
            
                 City c = cities.get(k);
                 if(prev==null || (Math.abs(prev.lat-c.lat)<=x && Math.abs(prev.lon-c.lon)<=y)){
                      sum+=c.points;
                      if(maxSum<sum){
                        maxSum=sum;
                      }
                      else if(sum < 0){
                          sum = 0;
                      }
                     prev=c;
                 }            
            }
        }
        
        return maxSum;
    }

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int x = in.nextInt();
        int y = in.nextInt();
        ArrayList<City> cities = new ArrayList<City>();
        for(int a0 = 0; a0 < n; a0++){
            int latitude = in.nextInt();
            int longitude = in.nextInt();
            int height = in.nextInt();
            int points = in.nextInt();
            // your code goes here
            cities.add(new City(latitude,longitude,height,points));
        }
        System.out.println(getMaxSum(cities,n,x,y));
    }
}