#include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for(ll i=0;i<n;i++)
#define repl(i,l,r) for(ll i=(l);i<(r);i++)
#define per(i,n) for(ll i=(n)-1;i>=0;i--)
#define perl(i,r,l) for(ll i=r-1;i>=l;i--)
#define fi first
#define se second
#define pb push_back
#define ins insert
#define pqueue(x) priority_queue<x,vector<x>,greater<x>>
#define all(x) (x).begin(),(x).end()
#define CST(x) cout<<fixed<<setprecision(x)
#define rev(x) reverse(x);
using ll=long long;
using vl=vector<ll>;
using vvl=vector<vector<ll>>;
using pl=pair<ll,ll>;
using vpl=vector<pl>;
using vvpl=vector<vpl>;
const ll MOD=1000000007;
const ll MOD9=998244353;
const int inf=1e9+10;
const ll INF=4e18;
const ll dy[8]={-1,0,1,0,1,1,-1,-1};
const ll dx[8]={0,-1,0,1,1,-1,1,-1};
template<class T> inline bool chmin(T& a, T b) {
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}
template<class T> inline bool chmax(T& a, T b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}

ll compress(vl &x){
  vl pls=x;
  sort(all(pls));
  pls.erase(unique(all(pls)),pls.end());
  rep(i,x.size()){
    x[i]=lower_bound(all(pls),x[i])-pls.begin();
  }
  return pls.size();
}
int main(){
  ll n,b;cin >> n >>b;
  vector<ll> x(n),y(n),p(n);
  rep(i,n)cin >> x[i] >> y[i] >> p[i];
  ll r=compress(x);
  ll c=compress(y);
  vvl cum(r+1,vl(c)),point(r+1,vl(c));
  rep(i,n){
    cum[x[i]+1][y[i]]+=p[i];
    point[x[i]+1][y[i]]++;
  }
  rep(i,r){
    rep(j,c){
      cum[i+1][j]+=cum[i][j];
      point[i+1][j]+=point[i][j];
    }
  }
  ll ans=0;
  rep(i,r){
    repl(j,i+1,r+1){
      vl pls(c+1),pointcum(c+1);
      rep(k,c){
        pls[k+1]=cum[j][k]-cum[i][k];
        pointcum[k+1]=point[j][k]-point[i][k];
      }
      rep(k,c){
        pls[k+1]+=pls[k];
        pointcum[k+1]+=pointcum[k];
      }
      rep(k,c+1){
        ll p=pls[k]-b;
        ll t=lower_bound(all(pls),p)-pls.begin();
        chmax(ans,pointcum[k]-pointcum[t]);
      }
    }
  }
  cout << ans <<endl;
}