#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <queue>
#include <string>
#include <map>
#include <set>
#include <stack>
#include <tuple>
#include <deque>
#include <array>
#include <numeric>
#include <bitset>
#include <iomanip>
#include <cassert>
#include <chrono>
#include <random>
#include <limits>
#include <iterator>
#include <functional>
#include <sstream>
#include <fstream>
#include <complex>
#include <cstring>
#include <unordered_map>
#include <unordered_set>
using namespace std;

using ll = long long;
constexpr int INF = 1001001001;
constexpr int mod = 1000000007;
// constexpr int mod = 998244353;

template<class T>
inline bool chmax(T& x, T y){
    if(x < y){
        x = y;
        return true;
    }
    return false;
}
template<class T>
inline bool chmin(T& x, T y){
    if(x > y){
        x = y;
        return true;
    }
    return false;
}

template<typename T>
struct CumulativeSum2D{
    vector<vector<T>> data;

    CumulativeSum2D(int W, int H) : data(W + 1, vector<T>(H + 1, 0)) {}

    void add(int x, int y, T z){
        ++x, ++y;
        if(x >= data.size() || y >= data[0].size()) return;
        data[x][y] += z;
    }

    void build(){
        for(int i = 1; i < (int)data.size(); ++i){
            for(int j = 1; j < (int)data[i].size(); ++j){
                data[i][j] += data[i][j - 1] + data[i - 1][j] - data[i - 1][j - 1];
            }
        }
    }

    T query(int sx, int sy, int gx, int gy){
        return (data[gx][gy] - data[sx][gy] - data[gx][sy] + data[sx][sy]);
    }
};

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int N, B;
    cin >> N >> B;
    vector<int> X(N), Y(N), P(N), xs, ys;
    for(int i = 0; i < N; ++i){
        cin >> X[i] >> Y[i] >> P[i];
        xs.emplace_back(X[i]);
        ys.emplace_back(Y[i]);
    }
    sort(begin(xs), end(xs));
    sort(begin(ys), end(ys));
    xs.erase(unique(begin(xs), end(xs)), end(xs));
    ys.erase(unique(begin(ys), end(ys)), end(ys));
    int H = xs.size(), W = ys.size();
    CumulativeSum2D<int> score(H, W), point(H, W);
    for(int i = 0; i < N; ++i){
        int x = lower_bound(begin(xs), end(xs), X[i]) - begin(xs);
        int y = lower_bound(begin(ys), end(ys), Y[i]) - begin(ys);
        score.add(x, y, P[i]);
        point.add(x, y, 1);
    }
    score.build();
    point.build();
    int ans = 0;
    for(int lx = 0; lx < H; ++lx){
        for(int rx = lx + 1; rx <= H; ++rx){
            for(int ly = 0; ly < W; ++ly){
                int low = ly, high = W + 1;
                while(high - low > 1){
                    int mid = (low + high) / 2;
                    if(score.query(lx, ly, rx, mid) <= B)   low = mid;
                    else    high = mid;
                }
                chmax(ans, point.query(lx, ly, rx, low));
            }
        }
    }
    cout << ans << endl;

    return 0;
}