#include<bits/stdc++.h>
namespace {
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-function"
#include<atcoder/all>
#pragma GCC diagnostic pop
using namespace std;
using namespace atcoder;
#define rep(i,n)for (int i = 0; i < int(n); ++i)
#define rrep(i,n)for (int i = int(n)-1; i >= 0; --i)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
template<class T> void chmax(T& a, const T& b) { a = max(a, b); }
template<class T> void chmin(T& a, const T& b) { a = min(a, b); }
using ll = long long;
using P = pair<int,int>;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<ll>;
using VVL = vector<VL>;

ll op(ll x, ll y) { return max(x, y); }
constexpr ll INF = 1002003004005006007;
ll e() { return -INF; }

template<class S>
struct value_compression : vector<S> {
  bool built = false;
  using VS = vector<S>;
  using VS::vector;
  value_compression(vector<S> v) : vector<S>(move(v)) {}
  void build() {
    sort(VS::begin(), VS::end());
    VS::erase(unique(VS::begin(), VS::end()), VS::end());
    built = true;
  }
  int operator()(S x) {
    assert(built);
    return lower_bound(VS::begin(), VS::end(), x) - VS::begin();
  }
  void clear() { VS::clear(); built = false; }
};

} int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n;
  cin >> n;
  VI t(n), x(n), v(n);
  rep(i, n) cin >> t[i] >> x[i] >> v[i];
  value_compression<int> idx(n + 1);
  rep(i, n) idx[i] = t[i] + x[i];
  idx.build();
  segtree<ll, op, e> seg(idx.size());
  seg.set(idx(0), 0);
  vector<int> ord(n);
  iota(ord.begin(), ord.end(), 0);
  sort(ord.begin(), ord.end(), [&](int i, int j) {
    return pair(t[i] - x[i], t[i] + x[i]) < pair(t[j] - x[j], t[j] + x[j]);
  });
  for (int i: ord) {
    if (t[i] - x[i] < 0) continue;
    int p = idx(t[i] + x[i]);
    ll t = seg.prod(0, p + 1) + v[i];
    seg.set(p, t);
  }
  cout << seg.all_prod() << '\n';
}