#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;
struct node{
    int lati , longi , height , point ;
} ;
int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    int n ;
    cin >> n ; int x , y ; cin >> x >> y ;
    vector< struct node > v(n) ;
    for( int i=0 ; i<n ; i++){ cin >>v[i].lati >> v[i].longi >> v[i].height >> v[i].point ;}
    long long int maxm=-99999999999999 ;
    for( int i=0 ; i<n ; i++ ){// cout<<"\ncame for "<<i ;
        long long int netpt=0 ;
        int hprev=-99999999 ; int latprev=v[i].lati ; int longprev=v[i].longi ;
        for( int j=i ; j<n ; j++){// cout<<"   -> "<<j;
            if(v[j].height>hprev and v[j].longi-longprev<=y and v[j].lati-latprev<=x ){
                latprev=v[j].lati ;
                longprev=v[j].longi ;
                hprev=v[j].height ;
                netpt+=v[j].point ; //cout<<"("<<netpt<<") ";
                if(netpt>maxm){
                    maxm=netpt ;
                }
            }
        }
    }
    cout<<maxm<<endl;
    return 0;
}