#include <iostream>
#include <vector>
#include <cstdio>
#include <sstream>
#include <map>
#include <string>
#include <algorithm>
#include <queue>
#include <cmath>
#include <set>
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];

	auto compress = [&](vector<int>& V){
		auto V__ = V;
		sort(V__.begin(), V__.end());
		V__.erase( unique(V__.begin(), V__.end()), V__.end());

		for(int i=0; i<N; i++){
			V[i] = lower_bound(V__.begin(), V__.end(), V[i]) - V__.begin();
		}
	};

	compress(X); compress(Y);

	int width = *max_element(X.begin(), X.end()) +1;
	int height = *max_element(Y.begin(), Y.end()) +1;

	vector<vector<int>> sum_p(width, vector<int>(height, 0));
	vector<vector<int>> sum_c(width, vector<int>(height, 0));
	for(int i=0; i<N; i++){
		sum_p[ X[i] ][ Y[i] ] += P[i];
		sum_c[ X[i] ][ Y[i] ] += 1;
	}

	for(int i=0; i<width; i++){
		for(int j=0; j<height; j++){
			if(j>0){
				sum_p[i][j] += sum_p[i][j-1];
				sum_c[i][j] += sum_c[i][j-1];
			}
			if(i>0){
				sum_p[i][j] += sum_p[i-1][j];
				sum_c[i][j] += sum_c[i-1][j];
			}
			if(i>0 && j>0){
				sum_p[i][j] -= sum_p[i-1][j-1];
				sum_c[i][j] -= sum_c[i-1][j-1];
			}
		}
	}

	//[ (a,b) , (c,d) ]
	auto get_points = [&](int a, int b, int c, int d){
		int ret = 0;
		ret += sum_p[c][d];
		if(a>0) ret -= sum_p[a-1][d];
		if(b>0) ret -= sum_p[c][b-1];
		if(a>0 && b>0) ret += sum_p[a-1][b-1];

		return ret;
	};


	//[ (a,b) , (c,d) ]
	auto get_counts = [&](int a, int b, int c, int d){
		int ret = 0;
		ret += sum_c[c][d];
		if(a>0) ret -= sum_c[a-1][d];
		if(b>0) ret -= sum_c[c][b-1];
		if(a>0 && b>0) ret += sum_c[a-1][b-1];

		return ret;
	};

	int ans = 0;
	for(int i=0; i<width; i++){
		for(int j=0; j<height; j++){
			int last = -1;
			for(int k=i; k<width; k++){
				int lb = j;
				int ub = height;
				if(last >= 0) ub = last+1;

				while(ub-lb>1){
					int med = (lb+ub)/2;
					int val = get_points(i,j, k,med);
					if(val > B){
						ub = med;
					}else{
						lb = med;
					}
				}

				if(get_points(i,j, k,lb) <= B)	ans = max(ans, get_counts(i,j, k,lb));

				last = lb;
			}
		}
	}

	cout << ans << endl;


	return 0;
}