import java.io.*;
import java.util.*;


public class Main_yukicoder165_1 {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        Printer pr = new Printer(System.out);

        int n = sc.nextInt();
        int b = sc.nextInt();

        int[] x = new int[n];
        int[] y = new int[n];
        int[] p = new int[n];
        SortedSet<Integer> tsx = new TreeSet<Integer>();
        SortedSet<Integer> tsy = new TreeSet<Integer>();
        int m = 0;
        for (int i = 0; i < n; i++) {
        	x[i] = sc.nextInt();
        	y[i] = sc.nextInt();
        	p[i] = sc.nextInt();

        	tsx.add(x[i]);
        	tsy.add(y[i]);
        	m++;
        }

        if (m == 0) {
        	pr.println(0);

        	pr.close();
        	sc.close();
        	return;
        }

        Map<Integer, Integer> hmx = new HashMap<>();
        Map<Integer, Integer> hmy = new HashMap<>();
        int ix = 1;
        for (int e : tsx) {
        	hmx.put(e, ix++);
        }
        int iy = 1;
        for (int e : tsy) {
        	hmy.put(e, iy++);
        }

        int cx = tsx.size();
        int cy = tsy.size();
        int[][] xy = new int[cx + 1][cy + 1];
        int[][] xyc = new int[cx + 1][cy + 1];
        for (int i = 0; i < n; i++) {
        	xy[hmx.get(x[i])][hmy.get(y[i])] = p[i];
        	xyc[hmx.get(x[i])][hmy.get(y[i])] = 1;
        }

        for (int i = 1; i <= cy; i++) {
        	for (int j = 1; j <= cx; j++) {
        		xy[j][i] += xy[j - 1][i];
        		xyc[j][i] += xyc[j - 1][i];
        	}
        }
    	for (int j = 1; j <= cx; j++) {
    		for (int i = 1; i <= cy; i++) {
        		xy[j][i] += xy[j][i - 1];
        		xyc[j][i] += xyc[j][i - 1];
        	}
        }

//        pr.printf("%d %d\n", cx, cy);

        int max = 0;
        for (int x1 = 0; x1 <= cx; x1++) {
        	for (int y1 = 0; y1 <= cy; y1++) {
        		int x2 = x1;
    			for (int ny2 = y1; ny2 <= cy; ny2++) {
    				int point = xy[x2][ny2] - xy[x2][y1] - xy[x1][ny2] + xy[x1][y1];

					int l = x2 - 1;
					int r = cx + 1;
					while (r - l > 1) {
						int mid = l + (r - l) / 2;
						point = xy[mid][ny2] - xy[mid][y1] - xy[x1][ny2] + xy[x1][y1];
						if (point > b) {
//						if (data[mid] > value) {
							r = mid;
						} else {
							l = mid;
						}
					}

					int cnt = xyc[r - 1][ny2] - xyc[r - 1][y1] - xyc[x1][ny2] + xyc[x1][y1];
					max = Math.max(max, cnt);
    			}
        	}
        }

        pr.println(max);

        pr.close();
        sc.close();
    }

	@SuppressWarnings("unused")
	private static class Scanner {
		BufferedReader br;
		Iterator<String> it;

		Scanner (InputStream in) {
			br = new BufferedReader(new InputStreamReader(in));
		}

		String next() throws RuntimeException  {
			try {
				if (it == null || !it.hasNext()) {
					it = Arrays.asList(br.readLine().split(" ")).iterator();
				}
				return it.next();
			} catch (IOException e) {
				throw new IllegalStateException();
			}
		}

		int nextInt() throws RuntimeException {
			return Integer.parseInt(next());
		}

		long nextLong() throws RuntimeException {
			return Long.parseLong(next());
		}

		float nextFloat() throws RuntimeException {
			return Float.parseFloat(next());
		}

		double nextDouble() throws RuntimeException {
			return Double.parseDouble(next());
		}

		void close() {
			try {
				br.close();
			} catch (IOException e) {
//				throw new IllegalStateException();
			}
		}
	}

	private static class Printer extends PrintWriter {
		Printer(PrintStream out) {
			super(out);
		}
	}
}