/* -*- coding: utf-8 -*-
 *
 * 165.cc: No.165 四角で囲え! - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int MAX_N = 400;

/* typedef */

typedef map<int,int> mii;

/* global variables */

int xs[MAX_N], ys[MAX_N], ps[MAX_N];
int xv[MAX_N], yv[MAX_N];
mii xmap, ymap;
int cs[MAX_N][MAX_N], csums[MAX_N + 1][MAX_N + 1];
int pas[MAX_N][MAX_N], psums[MAX_N + 1][MAX_N + 1];

/* subroutines */

inline int getcsum(int x0, int y0, int x1, int y1) { // [x0,x1), [y0,y1)
  return csums[y1][x1] - csums[y1][x0] - csums[y0][x1] + csums[y0][x0];
}

inline int getpsum(int x0, int y0, int x1, int y1) { // [x0,x1), [y0,y1)
  return psums[y1][x1] - psums[y1][x0] - psums[y0][x1] + psums[y0][x0];
}

/* main */

int main() {
  int n, b;
  cin >> n >> b;

  for (int i = 0; i < n; i++) {
    cin >> xs[i] >> ys[i] >> ps[i];
    xv[i] = xs[i], yv[i] = ys[i];
  }

  sort(xv, xv + n);
  int xn = unique(xv, xv + n) - xv;
  sort(yv, yv + n);
  int yn = unique(yv, yv + n) - yv;
  //printf("xn=%d,yn=%d\n", xn, yn);

  for (int i = 0; i < xn; i++) xmap[xv[i]] = i;
  for (int i = 0; i < yn; i++) ymap[yv[i]] = i;

  for (int i = 0; i < n; i++) {
    int gx = xmap[xs[i]], gy = ymap[ys[i]];
    cs[gy][gx] = 1;
    pas[gy][gx] = ps[i];
  }

  for (int gy = 0; gy < yn; gy++)
    for (int gx = 0; gx < xn; gx++) {
      csums[gy + 1][gx + 1] =
	cs[gy][gx] + csums[gy + 1][gx] + csums[gy][gx + 1] - csums[gy][gx];
      psums[gy + 1][gx + 1] =
	pas[gy][gx] + psums[gy + 1][gx] + psums[gy][gx + 1] - psums[gy][gx];
    }

  int maxc = 0;
  for (int gy0 = 0; gy0 < yn; gy0++)
    for (int gy1 = gy0 + 1; gy1 <= yn; gy1++) {
      int sum = 0;
      for (int gx0 = 0, gx1 = 0; gx1 <= xn; gx0++) {
	while (gx1 <= xn && getpsum(gx0, gy0, gx1, gy1) <= b) gx1++;
	int c = getcsum(gx0, gy0, gx1 - 1, gy1);
	if (maxc < c) maxc = c;
      }
    }

  printf("%d\n", maxc);
  return 0;
}