#include <iostream>
#include <algorithm>
#include <vector>
#include <map>
#include <functional>

template <class T>
std::map<T, int> compress(std::vector<T>& v) {
    std::sort(v.begin(), v.end());
    v.erase(std::unique(v.begin(), v.end()), v.end());

    std::map<T, int> rev;
    for (int i = 0; i < (int)v.size(); ++i) rev[v[i]] = i;
    return rev;
}

template <class T>
struct SegmentTree {
    using Merger = std::function<T(T, T)>;

    int length;
    std::vector<T> dat;
    T unit;
    Merger merge;

    SegmentTree() = default;

    SegmentTree(int n, const T& unit, const Merger& merge)
        : length(1), unit(unit), merge(merge) {
        while (length < n) length <<= 1;
        dat.assign(length * 2, unit);
    }

    template <class Container>
    SegmentTree(const Container& elems, const T& unit, const Merger& merge)
        : length(1), unit(unit), merge(merge) {
        int n = elems.size();
        while (length < n) length <<= 1;

        dat.assign(length * 2, unit);

        std::copy(elems.begin(), elems.end(), dat.begin() + length);

        for (int nidx = length - 1; nidx >= 1; --nidx) {
            T vl = dat[nidx * 2 + 0];
            T vr = dat[nidx * 2 + 1];
            dat[nidx] = merge(vl, vr);
        }
    }

    void update(int nidx, const T& elem) {
        nidx += length;
        dat[nidx] = elem;

        while (nidx > 0) {
            nidx >>= 1;
            T vl = dat[nidx * 2 + 0];
            T vr = dat[nidx * 2 + 1];
            dat[nidx] = merge(vl, vr);
        }
    }

    T fold(int ql, int qr) const {
        ql = std::max(ql, 0);
        qr = std::min(qr, length);
        ql += length, qr += length;

        T lacc = unit, racc = unit;
        while (ql < qr) {
            if (ql & 1) {
                lacc = merge(lacc, dat[ql]);
                ++ql;
            }
            if (qr & 1) {
                --qr;
                racc = merge(dat[qr], racc);
            }
            ql >>= 1, qr >>= 1;
        }

        return merge(lacc, racc);
    }

    T get(int idx) const { return dat[idx + length]; }
    T fold_all() const { return dat[1]; }
};

using lint = long long;

void solve() {
    int n;
    std::cin >> n;

    std::vector<int> ys;
    std::map<int, std::vector<std::pair<int, lint>>> tss;
    while (n--) {
        int x, y;
        lint c;
        std::cin >> x >> y >> c;

        ys.push_back(y);
        tss[x].emplace_back(y, c);
    }

    auto revy = compress(ys);
    int m = ys.size();

    SegmentTree<lint>
        seg(m, 0, [](auto a, auto b) { return std::max(a, b); });

    for (const auto& [x, ts] : tss) {
        std::vector<std::pair<int, lint>> updates;
        for (auto [y, c] : ts) {
            y = revy[y];
            lint score = seg.fold(0, y) + c;
            updates.emplace_back(y, score);
        }
        for (auto [y, score] : updates) {
            seg.update(y, std::max(seg.get(y), score));
        }
    }

    std::cout << seg.fold_all() << "\n";
}

int main() {
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);

    solve();

    return 0;
}