#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <chrono>
#include <cmath>
#include <complex>
#include <deque>
#include <forward_list>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iostream>
#include <limits>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <tuple>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
using namespace std;
using lint = long long;
using pint = pair<int, int>;
using plint = pair<lint, lint>;
struct fast_ios { fast_ios(){ cin.tie(nullptr), ios::sync_with_stdio(false), cout << fixed << setprecision(20); }; } fast_ios_;
#define ALL(x) (x).begin(), (x).end()
#define FOR(i, begin, end) for(int i=(begin),i##_end_=(end);i<i##_end_;i++)
#define IFOR(i, begin, end) for(int i=(end)-1,i##_begin_=(begin);i>=i##_begin_;i--)
#define REP(i, n) FOR(i,0,n)
#define IREP(i, n) IFOR(i,0,n)
template <typename T, typename V>
void ndarray(vector<T>& vec, const V& val, int len) { vec.assign(len, val); }
template <typename T, typename V, typename... Args> void ndarray(vector<T>& vec, const V& val, int len, Args... args) { vec.resize(len), for_each(begin(vec), end(vec), [&](T& v) { ndarray(v, val, args...); }); }
template <typename T> bool chmax(T &m, const T q) { return m < q ? (m = q, true) : false; }
template <typename T> bool chmin(T &m, const T q) { return m > q ? (m = q, true) : false; }
int floor_lg(long long x) { return x <= 0 ? -1 : 63 - __builtin_clzll(x); }
template <typename T1, typename T2> pair<T1, T2> operator+(const pair<T1, T2> &l, const pair<T1, T2> &r) { return make_pair(l.first + r.first, l.second + r.second); }
template <typename T1, typename T2> pair<T1, T2> operator-(const pair<T1, T2> &l, const pair<T1, T2> &r) { return make_pair(l.first - r.first, l.second - r.second); }
template <typename T> vector<T> sort_unique(vector<T> vec) { sort(vec.begin(), vec.end()), vec.erase(unique(vec.begin(), vec.end()), vec.end()); return vec; }
template <typename T> int arglb(const std::vector<T> &v, const T &x) { return std::distance(v.begin(), std::lower_bound(v.begin(), v.end(), x)); }
template <typename T> int argub(const std::vector<T> &v, const T &x) { return std::distance(v.begin(), std::upper_bound(v.begin(), v.end(), x)); }
template <typename T> istream &operator>>(istream &is, vector<T> &vec) { for (auto &v : vec) is >> v; return is; }
template <typename T> ostream &operator<<(ostream &os, const vector<T> &vec) { os << '['; for (auto v : vec) os << v << ','; os << ']'; return os; }
template <typename T, size_t sz> ostream &operator<<(ostream &os, const array<T, sz> &arr) { os << '['; for (auto v : arr) os << v << ','; os << ']'; return os; }
#if __cplusplus >= 201703L
template <typename... T> istream &operator>>(istream &is, tuple<T...> &tpl) { std::apply([&is](auto &&... args) { ((is >> args), ...);}, tpl); return is; }
template <typename... T> ostream &operator<<(ostream &os, const tuple<T...> &tpl) { os << '('; std::apply([&os](auto &&... args) { ((os << args << ','), ...);}, tpl); return os << ')'; }
#endif
template <typename T> ostream &operator<<(ostream &os, const deque<T> &vec) { os << "deq["; for (auto v : vec) os << v << ','; os << ']'; return os; }
template <typename T> ostream &operator<<(ostream &os, const set<T> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }
template <typename T, typename TH> ostream &operator<<(ostream &os, const unordered_set<T, TH> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }
template <typename T> ostream &operator<<(ostream &os, const multiset<T> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }
template <typename T> ostream &operator<<(ostream &os, const unordered_multiset<T> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }
template <typename T1, typename T2> ostream &operator<<(ostream &os, const pair<T1, T2> &pa) { os << '(' << pa.first << ',' << pa.second << ')'; return os; }
template <typename TK, typename TV> ostream &operator<<(ostream &os, const map<TK, TV> &mp) { os << '{'; for (auto v : mp) os << v.first << "=>" << v.second << ','; os << '}'; return os; }
template <typename TK, typename TV, typename TH> ostream &operator<<(ostream &os, const unordered_map<TK, TV, TH> &mp) { os << '{'; for (auto v : mp) os << v.first << "=>" << v.second << ','; os << '}'; return os; }
#ifdef HITONANODE_LOCAL
const string COLOR_RESET = "\033[0m", BRIGHT_GREEN = "\033[1;32m", BRIGHT_RED = "\033[1;31m", BRIGHT_CYAN = "\033[1;36m", NORMAL_CROSSED = "\033[0;9;37m", RED_BACKGROUND = "\033[1;41m", NORMAL_FAINT = "\033[0;2m";
#define dbg(x) cerr << BRIGHT_CYAN << #x << COLOR_RESET << " = " << (x) << NORMAL_FAINT << " (L" << __LINE__ << ") " << __FILE__ << COLOR_RESET << endl
#define dbgif(cond, x) ((cond) ? cerr << BRIGHT_CYAN << #x << COLOR_RESET << " = " << (x) << NORMAL_FAINT << " (L" << __LINE__ << ") " << __FILE__ << COLOR_RESET << endl : cerr)
#else
#define dbg(x) (x)
#define dbgif(cond, x) 0
#endif

// Range Minimum Query
// - RangeMinimumQuery<T, defaultT>(int N = 0) : Initialize array x = [defaultT, ..., defaultT] of
// length N, O(N)
// - RangeMinimumQuery<T, defaultT>(const std::vector<T> &vals) : Initialize array x by [vals[0],
// ..., vals[-1]], O(N)
// - update(int pos, T val) : x[pos] <- val, O(log N)
// - get(int begin, int end) : Get min(x_begin, ..., x_(end - 1)), O(log N)
template <typename T, T defaultT = std::numeric_limits<T>::max() / 2> struct RangeMinimumQuery {
    int N;
    int head;
    std::vector<T> x;
    T _get(int begin, int end, int pos, int l, int r) const {
        if (r <= begin or l >= end) return defaultT;
        if (l >= begin and r <= end) return x[pos];
        return std::min(_get(begin, end, 2 * pos + 1, l, (l + r) / 2),
                        _get(begin, end, 2 * pos + 2, (l + r) / 2, r));
    }
    RangeMinimumQuery(int N = 0) : N(N) {
        int N_tmp = 1;
        while (N_tmp < N) N_tmp <<= 1;
        x.assign(N_tmp * 2, defaultT), head = N_tmp - 1;
    }
    void _build(const std::vector<T> &vals) {
        std::copy(vals.begin(), vals.end(), x.begin() + head);
        for (int i = head - 1; i >= 0; i--) x[i] = std::min(x[i * 2 + 1], x[i * 2 + 2]);
    }
    RangeMinimumQuery(const std::vector<T> &vals) : N(vals.size()) {
        int N_tmp = 1;
        while (N_tmp < N) N_tmp <<= 1;
        x.assign(N_tmp * 2, defaultT), head = N_tmp - 1;
        _build(vals);
    }
    void update(int pos, T val) {
        pos += head, x[pos] = val;
        while (pos) pos = (pos - 1) / 2, x[pos] = std::min(x[pos * 2 + 1], x[pos * 2 + 2]);
    }
    T get(int begin, int end) const { return _get(begin, end, 0, 0, (int)x.size() / 2); }
    friend std::ostream &operator<<(std::ostream &os, const RangeMinimumQuery &s) {
        os << '[';
        for (int i = 0; i < s.N; i++) os << s.get(i, i + 1) << ',';
        return os << ']';
    }
};


int main() {
    int N;
    cin >> N;
    vector<tuple<int, int, int>> uvws;
    while (N--) {
        int t, x, w;
        cin >> t >> x >> w;
        if (t < abs(x)) continue;
        int u = t + x, v = t - x;
        uvws.emplace_back(u, v, w);
    }
    sort(uvws.begin(), uvws.end());
    dbg(uvws);

    if (uvws.empty()) {
        puts("0");
        return 0;
    }

    vector<int> vs;
    for (auto [u, v, w] : uvws) {
        vs.push_back(v);
    }
    vs = sort_unique(vs);
    for (auto &[u, v, w] : uvws) v = arglb(vs, v);

    RangeMinimumQuery<lint> rmq(vs.size());
    rmq.update(0, 0);
    for (auto [u, v, w] : uvws) {
        lint val = -rmq.get(0, v + 1);
        chmax(val, 0LL);
        val += w;
        if (-rmq.get(v, v + 1) < val) {
            rmq.update(v, -val);
        }
    }
    cout << -rmq.get(0, vs.size()) << '\n';
}