#include <iostream>
#include <vector>
#include <map>
#include <algorithm>
using namespace std;
int main(){
	int N, B;
	cin >> N >> B;
	vector<int> X(N), Y(N), P(N);
	for (int i = 0; i < N; i++){
		cin >> X[i] >> Y[i] >> P[i];
	}
	int ans = 0;
	for (int i = 0; i < N; i++){
		for (int j = i; j < N; j++){
			int D = min(Y[i], Y[j]);
			int U = max(Y[i], Y[j]);
			map<int, int> p, c;
			for (int k = 0; k < N; k++){
				if (D <= Y[k] && Y[k] <= U){
					p[X[k]] += P[k];
					c[X[k]]++;
				}
			}
			vector<int> p2;
			for (auto x : p){
				p2.push_back(x.second);
			}
			vector<int> c2;
			for (auto x : c){
				c2.push_back(x.second);
			}
			int cnt = p2.size();
			vector<int> sp(cnt + 1);
			sp[0] = 0;
			for (int k = 0; k < cnt; k++){
				sp[k + 1] = sp[k] + p2[k];
			}
			vector<int> sc(cnt + 1);
			sc[0] = 0;
			for (int k = 0; k < cnt; k++){
				sc[k + 1] = sc[k] + c2[k];
			}
			for (int k = 0; k <= cnt; k++){
				ans = max(ans, sc[upper_bound(sp.begin(), sp.end(), sp[k] + B) - sp.begin() - 1] - sc[k]);
			}
		}
	}
	cout << ans << endl;
}