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

public class Solution {
    
    static boolean visited[];
    static int dp[];
    static HashMap<Integer, Quad> map = new HashMap<Integer, Quad>();
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int x = in.nextInt();
        int y = in.nextInt();
        Quad [] quads = new Quad [n];
        visited = new boolean[n];
        dp = new int[n];
        for(int a0 = 0; a0 < n; a0++){
            
            int latitude = in.nextInt();
            int longitude = in.nextInt();
            int height = in.nextInt();
            int points = in.nextInt();
            quads[a0] = new Quad(latitude, longitude, height, points);
            quads[a0].id = a0;
            map.put(a0, quads[a0]);
        }
        Arrays.sort(quads);
        for(int a= 0; a < n; a++)
        {
          for(int b = a+1; b < n; b++)
          {
          if(Math.abs(quads[a].latitude- quads[b].latitude) <= x && Math.abs(quads[a].longitude- quads[b].longitude) <= y)
                    {
                 quads[a].adjList.add(quads[b].id);       
            }
           }
        }
        int maxPoints = Integer.MIN_VALUE;
       
        for(int c = 0; c < n ; c++)
            {
            if(!visited[c])
                {
                maxPoints = Math.max(maxPoints, (dp[c] = dfs(c)));
            }
            else
                {
                maxPoints = Math.max(maxPoints, dp[c]);
            }
        }
        
        System.out.println(maxPoints);    
    }
    
    public static int dfs(int c)
        {
        visited[c] = true;
        int ans = map.get(c).points;
        for(Integer adj: map.get(c).adjList)
            {
            if(!visited[adj])
                ans = Math.max(ans , map.get(c).points + dfs(adj));
            else
                ans = Math.max(ans, map.get(c).points + dp[adj]);
        }
        return (dp[c] = ans);
    }
    
    public static class Quad implements Comparable<Quad>
        {
        public int id;
        public int latitude;
        public int longitude;
        public int height;
        public int points;
        List<Integer> adjList = new ArrayList<Integer>();
        @Override
        public int compareTo(Quad other){
            return this.height - other.height;
        }
        public Quad(int latitude, int longitude, int height, int points)
            {
            this.latitude = latitude;
            this.longitude = longitude;
            this.height = height;
            this.points = points;
        }
    }
}