/**
 *   @FileName	a.cpp
 *   @Author	kanpurin
 *   @Created	2022.01.31 09:12:44
**/

#include "bits/stdc++.h" 
using namespace std; 
typedef long long ll;


struct P {
    ll t,x,v;
    bool operator<(P p) {
        if (t+x != p.t+p.x)
            return t+x < p.t+p.x;
        else
            return t < p.t;
    }
};

template< typename Monoid >
struct DynamicSegmentTree {
private:
    struct Node;
    using Func = function<Monoid(Monoid,Monoid)>;
    using node_ptr = unique_ptr<Node>;
    Func F;
    Monoid e;
    size_t n;
    struct Node {
        size_t index;
        Monoid value,prod;
        node_ptr left, right;
        Node(size_t index, Monoid value) : index(index),
                                           value(value),
                                           prod(value),
                                           left(nullptr),
                                           right(nullptr) {}
    };
    
    void node_update(node_ptr &np) const {
        np->prod = F(F(np->left?np->left->prod:e,np->value),
                       np->right?np->right->prod:e);
    }

    void _update(node_ptr& t, size_t a, size_t b, size_t p, Monoid &val) const {
        if (!t) {
            t = make_unique<Node>(p, val);
            return;
        }
        if (t->index == p) {
            t->value = val;
            node_update(t);
            return;
        }
        size_t c = (a+b)/2;
        if (p < c) {
            if (t->index < p) swap(t->index,p), swap(t->value,val);
            _update(t->left,a,c,p,val);
        }
        else {
            if (p < t->index) swap(p,t->index), swap(val,t->value);
            _update(t->right,c,b,p,val);
        }
        node_update(t);
    }

    Monoid _get(const node_ptr& t, size_t a, size_t b, size_t l, size_t r) const {
        if (!t || b <= l || r <= a) return e;
        if (l <= a && b <= r) return t->prod;
        size_t c = (a + b) / 2;
        Monoid result = _get(t->left, a, c, l, r);
        if (l <= t->index && t->index < r) result = F(result, t->value);
        return F(result, _get(t->right, c, b, l, r));
    }

    size_t _binary_search(const node_ptr& t, 
                       size_t a, size_t b, 
                       const function<bool(Monoid)> &f, 
                       Monoid &s, 
                       size_t l, size_t r) {
        if (!t || r <= a || b <= l) return n;
        if (a <= l && r <= b && !f(F(s,t->prod))) {
            s = F(s,t->prod);
            return n;
        }
        size_t ret = _binary_search(t->left,a,b,f,s,l,(r-l)/2+l);
        if (ret != n) return ret;
        if (a <= t->index) {
            s = F(s,t->value);
            if (f(s)) return t->index;
        }
        return _binary_search(t->right,a,b,f,s,(r-l)/2+l,r);
    }

    void _print(node_ptr& t) {
        if (!t) return;
        _print(t->left);
        _print(t->right);
        cout << "[" << t->index << "] : " << t->value << endl;
    }

    node_ptr root;
public:
    DynamicSegmentTree(size_t n,
                       const Func f,
                       const Monoid &e) : n(n),F(f),e(e),root(nullptr) {}

    void update_query(size_t x, Monoid val) {
        assert(x < n);
        _update(root, 0, n, x, val);
    }

    Monoid get_query(size_t l, size_t r) const {
        assert(l <= r && r <= n);
        return _get(root, 0, n, l, r);
    }

    size_t binary_search(size_t l, size_t r, const function<bool(Monoid)> &f) {
        Monoid s = e;
        size_t ret = _binary_search(root,l,r,f,s,0,n);
        return ret != n ? ret : -1;
    }

    Monoid operator[](int x) const {
        return get_query(x,x+1);
    }
    
    size_t size() {
        return n;
    }

    void print() {
        _print(root);
    }
};

constexpr long long LLINF = 1e18 + 1;

int main() {
    int n;cin >> n;
    vector<P> a(n);
    for (int i = 0; i < n; i++) {
        cin >> a[i].t >> a[i].x >> a[i].v;
    }
    a.push_back({0,0,0});
    n++;
    sort(a.begin(), a.end());
    DynamicSegmentTree<ll> seg(3LL*1000000000,[](ll x,ll y){return max(x,y);},-LLINF);
    for (int i = 0; i < n; i++) {
        if (a[i].v == 0) {
            seg.update_query(1000000000,0);
            continue;
        }
        ll v = seg.get_query(0,a[i].t-a[i].x+1000000001);
        if (seg.get_query(a[i].t-a[i].x+1000000000,a[i].t-a[i].x+1000000001) >= v+a[i].v) continue;
        seg.update_query(a[i].t-a[i].x+1000000000,v+a[i].v);
    }
    cout << seg.get_query(0,3LL*1000000000) << endl;
    return 0;
}