#include <bits/stdc++.h>
#include<algorithm>
using namespace std;

/* C program for Merge Sort */
#include<stdlib.h>
#include<stdio.h>
 
// Merges two subarrays of arr[].
// First subarray is arr[l..m]
// Second subarray is arr[m+1..r]
void merge(long int *arr[], int l, int m, int r)
{
    long int i, j, k;
    long int n1 = m - l + 1;
    long int n2 =  r - m;
 
    /* create temp arrays */
    long int *L[n1];
    long int *R[n2];
 
    /* Copy data to temp arrays L[] and R[] */
    for (i = 0; i < n1; i++)
        L[i] = arr[l + i];
    for (j = 0; j < n2; j++)
        R[j] = arr[m + 1+ j];
 
    /* Merge the temp arrays back into arr[l..r]*/
    i = 0; // Initial index of first subarray
    j = 0; // Initial index of second subarray
    k = l; // Initial index of merged subarray
    while (i < n1 && j < n2)
    {
        if (L[i][2] <= R[j][2])
        {
            arr[k] = L[i];
            i++;
        }
        else
        {
            arr[k] = R[j];
            j++;
        }
        k++;
    }
 
    /* Copy the remaining elements of L[], if there
       are any */
    while (i < n1)
    {
        arr[k] = L[i];
        i++;
        k++;
    }
 
    /* Copy the remaining elements of R[], if there
       are any */
    while (j < n2)
    {
        arr[k] = R[j];
        j++;
        k++;
    }
}
 
/* l is for left index and r is right index of the
   sub-array of arr to be sorted */
void mergeSort(long int *arr[], int l, int r)
{
    if (l < r)
    {
        // Same as (l+r)/2, but avoids overflow for
        // large l and h
        int m = l+(r-l)/2;
 
        // Sort first and second halves
        mergeSort(arr, l, m);
        mergeSort(arr, m+1, r);
 
        merge(arr, l, m, r);
    }
}
 
int main(){
    int n;
    int x;
    int y;
    cin >> n >> x >> y;
    long int *ar[n];
    for(long int i=0;i<n;i++)
    {    ar[i]=new long int[4];
        cin>>ar[i][0]>>ar[i][1]>>ar[i][2]>>ar[i][3];
    }
   mergeSort(ar,0,n-1);
   long int points=0,prevlat,prevlong,max=-200000;
   for(long int i=0;i<n;i++)
       {   points=ar[i][3];
           prevlat=ar[i][0];
           prevlong=ar[i][1];
       for(long int j=i+1;j<n;j++)
           {
                 if(ar[j][0]-prevlat<=x && ar[j][1]-prevlong<=y)
                     {
                     prevlat=ar[j][0];
                     prevlong=ar[j][1];
                     points+=ar[j][3];
                 }
           if(points>max)
               max=points;
       }
   }
    cout<<max;
    
    
    
    
 
    
    return 0;
}