#include <algorithm>
#include <atcoder/lazysegtree.hpp>
#include <atcoder/segtree.hpp>
#include <cassert>
#include <cmath>
#include <cstring>
#include <deque>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <set>
#include <tuple>
#include <utility>
#include <vector>
using namespace std;
using i8 = int8_t;
using i32 = int;
using i64 = long long;
// using i128 = __int128;
using u64 = unsigned long long;
using ll = long long;

void _main();
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  _main();
}

i64 pow(i64 j, i64 n) {
  i64 res = 1;
  while (n > 0) {
    if (n & 1)
      res *= j;
    j *= j;
    n >>= 1;
  }
  return res;
}

i64 op(i64 a, i64 b) { return max(a, b); }
i64 e() { return 0; }
i64 m(i64 f, i64 x) { return x + f; }
i64 comp(i64 f, i64 g) { return f + g; }

i64 n, s, h;
void _main() {
  cin >> n >> s >> h;
  vector<i64> x(n);
  vector<i64> y(n);
  vector<i64> z(n);
  for (i64 i = 0; i < n; i++) {
    cin >> x[i] >> y[i] >> z[i];
  }
  atcoder::segtree<i64, op, e> xs(n);
  atcoder::lazy_segtree<i64, op, e, i64, m, comp, e> ys(n);
  atcoder::lazy_segtree<i64, op, e, i64, m, comp, e> add(n);
  i64 ans = 0;
  for (i64 i = n - 1; i >= 0; i--) {
    i64 a = upper_bound(x.begin(), x.end(), y[i] + h) - x.begin();
    if (a < n) {
      ys.set(i, xs.prod(a, n));
    }
    i64 b = upper_bound(y.begin(), y.end(), x[i] + s) - y.begin();
    ys.apply(i, b, z[i]);
    add.apply(i, b, z[i]);
    for (i64 j = b; j < n; j++) {
      if (add.get(j) == 0) {
        break;
      }
      add.set(j, 0);
    }
    xs.set(i, ys.prod(i, n));
    ans = max(ans, xs.get(i));
  }
  cout << ans << "\n";
}