#pragma GCC optimize ("O3")
#pragma GCC target ("avx")
#include "bits/stdc++.h" // define macro "/D__MAI"

using namespace std;
typedef long long int ll;

#define xprintf(fmt,...) fprintf(stderr,fmt,__VA_ARGS__)
#define debugv(v) {printf("L%d %s > ",__LINE__,#v);for(auto e:v){cout<<e<<" ";}cout<<endl;}
#define debuga(m,w) {printf("L%d %s > ",__LINE__,#m);for(int x=0;x<(w);x++){cout<<(m)[x]<<" ";}cout<<endl;}
#define debugaa(m,h,w) {printf("L%d %s >\n",__LINE__,#m);for(int y=0;y<(h);y++){for(int x=0;x<(w);x++){cout<<(m)[y][x]<<" ";}cout<<endl;}}
#define ALL(v) (v).begin(),(v).end()
#define repeat(cnt,l) for(auto cnt=0ll;cnt<(l);++cnt)
#define iterate(cnt,b,e) for(auto cnt=(b);cnt!=(e);++cnt)
#define MD 1000000007ll
#define PI 3.1415926535897932384626433832795
#define EPS 1e-12
template<typename T1, typename T2> ostream& operator <<(ostream &o, const pair<T1, T2> p) { o << "(" << p.first << ":" << p.second << ")"; return o; }
template<typename iterator> inline size_t argmin(iterator begin, iterator end) { return distance(begin, min_element(begin, end)); }
template<typename iterator> inline size_t argmax(iterator begin, iterator end) { return distance(begin, max_element(begin, end)); }
template<typename T> T& maxset(T& to, const T& val) { return to = max(to, val); }
template<typename T> T& minset(T& to, const T& val) { return to = min(to, val); }

mt19937_64 randdev(8901016);
inline ll rand_range(ll l, ll h) {
    return uniform_int_distribution<ll>(l, h)(randdev);
}

#ifdef __MAI
#define getchar_unlocked getchar
#define putchar_unlocked putchar
#endif
#ifdef __VSCC
#define getchar_unlocked _getchar_nolock
#define putchar_unlocked _putchar_nolock
#endif
namespace {
#define isvisiblechar(c) (0x21<=(c)&&(c)<=0x7E)
    class MaiScanner {
    public:
        template<typename T> void input_integer(T& var) {
            var = 0;
            T sign = 1;
            int cc = getchar_unlocked();
            for (; cc<'0' || '9'<cc; cc = getchar_unlocked())
                if (cc == '-') sign = -1;
            for (; '0' <= cc&&cc <= '9'; cc = getchar_unlocked())
                var = (var << 3) + (var << 1) + cc - '0';
            var = var*sign;
        }
        inline int c() { return getchar_unlocked(); }
        inline MaiScanner& operator>>(int& var) {
            input_integer<int>(var);
            return *this;
        }
        inline MaiScanner& operator>>(long long& var) {
            input_integer<long long>(var);
            return *this;
        }
        inline MaiScanner& operator>>(string& var) {
            int cc = getchar_unlocked();
            for (; !isvisiblechar(cc); cc = getchar_unlocked());
            for (; isvisiblechar(cc); cc = getchar_unlocked())
                var.push_back(cc);
            return *this;
        }
        template<typename IT> void in(IT begin, IT end) {
            for (auto it = begin; it != end; ++it) *this >> *it;
        }
    };
}
MaiScanner scanner;




ll m, n, bound;

vector<array<int, 3>> points;

ll field[410][410];
int exists[410][410];

int main() {

    scanner >> n >> bound;
    points.reserve(n);

    // 座標圧縮用
    map<int, int> zip_x;
    map<int, int> zip_y;

    repeat(i, n) {
        int x, y, p;
        scanner >> x >> y >> p;
        points.push_back({ x,y,p });
        zip_x[x] = zip_y[y] = 0;
    }

    {
        int i = 0;
        for (auto& p : zip_x)
            p.second += i++;
    }
    {
        int i = 0;
        for (auto& p : zip_y)
            p.second += i++;
    }

    // 座圧後，二次元配列にセット
    for (auto& a : points) {
        int x = a[0] = zip_x[a[0]];
        int y = a[1] = zip_y[a[1]];

        field[y][x + 1] = a[2];
        exists[y][x + 1] = 1;
    }

    // 累積和
    for (int y = 0; y < 405; ++y) {
        for (int x = 0; x < 405; ++x) {
            field[y][x + 1] += field[y][x];
            exists[y][x + 1] += exists[y][x];
        }
    }

    int best = 0;

    for (int left = 0; left < 405 - 1; ++left) {
        for (int right = left + 1; right < 405; ++right) {
            int score = 0;
            int count = 0;
            // しゃくとり
            int bottom = 0;
            for (int y = 0; y < 405; ++y) {
                score += field[y][right] - field[y][left];
                count += exists[y][right] - exists[y][left];
                while (score > bound) {
                    score -= field[bottom][right] - field[bottom][left];
                    count -= exists[bottom][right] - exists[bottom][left];
                    ++bottom;
                }
                maxset(best, count);
            }
        }
    }

    cout << best << endl;

    return 0;
}