#include <bits/stdc++.h>
using namespace std;
typedef tuple<int, int, int> T;
typedef pair<int, int> P;

int main() {
    int N, B; cin >> N >> B;
    vector<T> XYP;
    
    for (int i=0; i<N; i++) {
        int Xi, Yi, Pi; cin >> Xi >> Yi >> Pi;
        XYP.push_back(make_tuple(Xi, Yi, Pi));
    }
    
    sort(XYP.begin(), XYP.end(), [](T const &t1, T const &t2){return get<0>(t1)<get<0>(t2);});
    int ans = 0;
    
    for (int i=0; i<N; i++) {
        int Xi = get<0>(XYP[i]);
        
        for (int j=i; j<N; j++) {
            int Xj = get<0>(XYP[j]);
            vector<P> YP;
            
            for (int k=0; k<N; k++) {
                int Xk = get<0>(XYP[k]);
                int Yk = get<1>(XYP[k]);
                int Pk = get<2>(XYP[k]);
                
                if (Xi<=Xk && Xk<=Xj) {
                    YP.push_back(P(Yk, Pk));
                }
            }
            
            sort(YP.begin(), YP.end(), [](P const &p1, P const &p2){return p1.first<p2.first;});
            vector<int> cnt;
            vector<int> point;
            int c = 0;
            int p = 0;
            
            for (int k=0; k<YP.size()-1; k++) {
                c += 1;
                p += YP[k].second;
                
                if (YP[k].first!=YP[k+1].first) {
                    cnt.push_back(c);
                    point.push_back(p);
                    c = 0;
                    p = 0;
                }
            }
            
            c += 1;
            p += YP[YP.size()-1].second;
            cnt.push_back(c);
            point.push_back(p);
            vector<int> c_acc = {0};
            vector<int> p_acc = {0};
            
            for (auto& cnt_i : cnt) {
                c_acc.push_back(c_acc[c_acc.size()-1]+cnt_i);
            }
            
            for (auto& point_i : point) {
                p_acc.push_back(p_acc[p_acc.size()-1]+point_i);
            }
            
            for (int k=0; k<c_acc.size(); k++) {
                int mark = distance(p_acc.begin(), upper_bound(p_acc.begin(), p_acc.end(), p_acc[k]+B))-1;
                ans = max(ans, c_acc[mark]-c_acc[k]);
            }
        }
    }
    
    cout << ans << endl;
}