#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
//using mint = modint1000000007;
//const int mod = 1000000007;
//using mint = modint998244353;
//const int mod = 998244353;
//const int INF = 1e9;
const long long LINF = 1e18;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep2(i,l,r)for(int i=(l);i<(r);++i)
#define rrep(i, n) for (int i = (n-1); i >= 0; --i)
#define rrep2(i,l,r)for(int i=(r-1);i>=(l);--i)
#define all(x) (x).begin(),(x).end()
#define allR(x) (x).rbegin(),(x).rend()
#define endl "\n"
#define P pair<long long,long long>
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }
long long op(long long a, long long b) { return max(a, b); }
long long e() { return -LINF; }
map<long long, long long> Compless(const vector<long long> &v) {
	vector<long long>vv = v;
	sort(all(vv));
	vv.erase(unique(all(vv)), vv.end());
	map<long long, long long>mp;
	rep(i, vv.size()) mp[vv[i]] = i;
	return mp;
}
int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int n; cin >> n;
	vector<pair<P, long long>>vec;
	vec.push_back({ {0 - 0,0 + 0},0 });
	rep(i, n) {
		int t, x, v; cin >> t >> x >> v;
		if (t - x >= 0)vec.push_back({ {t - x,t + x},v });
	}
	sort(all(vec));
	vector<long long>memo;
	rep(i, vec.size())memo.push_back(vec[i].first.second);
	memo.push_back(0);
	//
	vector<long long>vv = memo;
	sort(all(vv));
	vv.erase(unique(all(vv)), vv.end());
	map<long long, long long>mp;
	rep(i, vv.size()) mp[vv[i]] = i;
	//
	segtree<long long, op, e>seg(mp.size());
	seg.set(mp[0], 0);
	rep(i, vec.size()) {
		int idx = mp[vec[i].first.second];
		long long get = seg.prod(0, idx + 1);
		if (-LINF == get)continue;
		seg.set(idx, get + vec[i].second);
	}
	cout << seg.all_prod() << endl;
	return 0;
}