#include <bits/stdc++.h>

typedef long long ll;
typedef unsigned long long ull;

#define FOR(i,a,b) for(int (i)=(a);i<(b);i++)
#define REP(i,n) FOR(i,0,n)
#define RANGE(vec) (vec).begin(),(vec).end()

using namespace std;

pair<ll,ll> operator+(const pair<ll,ll> &a, const pair<ll,ll> &b)
{
    return make_pair(a.first+b.first, a.second+b.second);
}
pair<ll,ll> operator-(const pair<ll,ll> &a, const pair<ll,ll> &b)
{
    return make_pair(a.first-b.first, a.second-b.second);
}
class SurroundWithSquare {
public:
    void dump(const pair<ll,ll> &a) {
        cerr<<a.first<<","<<a.second<<endl;
    }
    void solve(void)
    {
        int N,B;
        cin>>N>>B;

        // 座標圧縮を使う
        vector<ll> xs;
        vector<ll> ys;
        vector<tuple<ll,ll,ll>> ps;
        REP(i,N)
        {
            ll x,y,p;
            cin>>x>>y>>p;
            ps.emplace_back(x,y,p);
            xs.push_back(x);
            ys.push_back(y);
        }
        sort(RANGE(xs));
        sort(RANGE(ys));

        map<ll,int> xmap;
        map<ll,int> ymap;
        REP(i,N)
        {
            xmap.emplace(xs[i],xmap.size());
            ymap.emplace(ys[i],ymap.size());
        }
        const int maxX = xmap.size();
        const int maxY = ymap.size();

        // 0<=x,y<400
        pair<ll,ll> field[maxY][maxX];
        REP(y,maxY) REP(x,maxX) field[y][x] = make_pair(0,0);

        REP(i,N)
        {
            ll x,y,p;
            tie(x,y,p) = ps[i];
            field[ymap[y]][xmap[x]] = make_pair(p,1);
        }
        pair<ll,ll> Sum[maxY+1][maxX+1];

        // 累積和を計算する(レンジは半開区間)
        REP(y,maxY)
        REP(x,maxX)
            Sum[y+1][x+1] = field[y][x];
        REP(y,maxY+1)
        REP(x,maxX)
        {
            Sum[y][x+1] = Sum[y][x+1] + Sum[y][x];
        }
        REP(y,maxY)
        REP(x,maxX+1)
        {
            Sum[y+1][x] = Sum[y+1][x] + Sum[y][x];
        }

        // 二分探索を使って高速化する O(N^3*log(N))
        ll maxN = 0;
        REP(uy,maxY+1)
        REP(ly,uy+1)
        REP(lx,maxX+1)
        {
            int low = 0;
            int high = maxX-lx+1;
            ll  n    = 0;

            // ly,uy,lx を固定したとき cnt は ux に対して単調増加なので二分探索できる
            while (low+1 < high)
            {
                int mid = (low+high)/2;
                int ux = lx + mid;
                pair<ll,ll> cnt(0,0);

                cnt = Sum[uy][ux] - Sum[uy][lx] - Sum[ly][ux] + Sum[ly][lx];
                if (cnt.first <= B)
                {
                    low = mid;
                    n = cnt.second;
                }
                else
                    high = mid;
            }
            maxN = max(maxN, n);
        }
        cout<<maxN<<endl;
    }
};

#if 1
int main(int argc, char *argv[])
{
        ios::sync_with_stdio(false);
        auto obj = new SurroundWithSquare();
        obj->solve();
        delete obj;
        return 0;
}
#endif