#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;

struct city {
    int x, y, h, p;
    city(int x = 0, int y = 0, int h = 0, int p = 0): x(x), y(y), h(h), p(p) {
    }
    
    bool operator < (const city& oth) {
        return h < oth.h;
    }
};

const int MAX_N = 200005;

int n, x, y;
long long dp[MAX_N];
city c[MAX_N];

int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */ 
    cin >> n >> x >> y; 
    for (int i = 0; i < n; i++) {
        cin >> c[i].x >> c[i].y >> c[i].h >> c[i].p;
    }
    sort(c, c + n);
    for (int i = 0; i < n; i++) {
        dp[i] = max(0, c[i].p);
        for (int j = 0; j < i; j++) {
            if (c[i].h > c[j].h && abs(c[i].x - c[j].x) <= x && abs(c[i].y - c[j].y) <= y) {
                dp[i] = max(dp[i], dp[j] + c[i].p);
            }
        }
    }
    long long ans = 0;
    for (int i = 0; i < n; i++) {
        ans =max(ans, dp[i]);

    }
    cout << ans << endl;
    return 0;
}