#include <sstream>
#include <string>
#include <vector>
#include <map>
#include <algorithm>
#include <iostream>
#include <utility>
#include <set>
#include <cctype>
#include <queue>
#include <stack>
#include <cstdio>
#include <cstdlib>
#include <cmath>

using namespace std;
typedef long long ll;

const int MAXN = 410;
int X[MAXN], Y[MAXN], P[MAXN];
int points[MAXN][MAXN];
int sumPoint[MAXN][MAXN];
int pointNum[MAXN][MAXN];
int xsize, ysize;
int N, B;

int getPoint(int x1, int x2, int y1, int y2) {
    return sumPoint[y2][x2] - sumPoint[y2][x1-1] - sumPoint[y1-1][x2] + sumPoint[y1-1][x1-1];
}

int getNumPoint(int x1, int x2, int y1, int y2) {
    return pointNum[y2][x2] - pointNum[y2][x1-1] - pointNum[y1-1][x2] + pointNum[y1-1][x1-1];
}

int maxPoint(int x1, int x2) {
    int ret = 0;
    int y1 = 1, y2 = 1;
    for (;y2 <= ysize; y2++) {
        while (getPoint(x1, x2, y1, y2) > B) y1++;
        ret = max(ret, getNumPoint(x1, x2, y1, y2));
    }
    return ret;
}

int main(void) {
    cin >> N >> B;
    vector<int> xs, ys;
    for (int i = 0; i < N; i++) {
        cin >> X[i] >> Y[i] >> P[i];
        xs.push_back(X[i]);
        ys.push_back(Y[i]);
    }
    sort(xs.begin(), xs.end());
    xs.erase(unique(xs.begin(), xs.end()), xs.end());
    sort(ys.begin(), ys.end());
    ys.erase(unique(ys.begin(), ys.end()), ys.end());
    for (int i = 0; i < N; i++) {
        int x = lower_bound(xs.begin(), xs.end(), X[i]) - xs.begin();
        int y = lower_bound(ys.begin(), ys.end(), Y[i]) - ys.begin();
        points[y][x] = P[i];
    }
    xsize = xs.size();
    ysize = ys.size();
    for (int i = 1; i <= ysize; i++) {
        for (int j = 1; j <= xsize; j++) {
            sumPoint[i][j] = sumPoint[i-1][j] + sumPoint[i][j-1] - sumPoint[i-1][j-1] + points[i-1][j-1];
            pointNum[i][j] = pointNum[i-1][j] + pointNum[i][j-1] - pointNum[i-1][j-1];
            if (points[i-1][j-1] > 0) pointNum[i][j]++;
        }
    }
//    for (int i = 0; i <= ysize; i++) {
//        for (int j = 0; j <= xsize; j++) {
//            cout << sumPoint[i][j] << "  ";
//        }
//        cout << endl;
//    }
    int ret = 0;
    for (int i = 0; i <= xsize; i++) {
        for (int j = i; j <= xsize; j++) {
            ret = max(ret, maxPoint(i, j));
        }
    }
    cout << ret << endl;
    return 0;
}