#include <stdio.h>
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using mint = modint998244353;
using namespace std;
#define rep(i,n) for(int i=0;i<(n);i++)
#define Inf 1000000000000000001;

long long op(long long a,long long b){
	return max(a,b);
}

long long e(){
	return -Inf;
}

int main(){
	
	int n;
	cin>>n;
	
	vector<array<long long,3>> a(n);
	rep(i,n){
		long long t,x,v;
		cin>>t>>x>>v;
		a[i][0] = t+x;
		a[i][1] = t-x;
		a[i][2] = v;
	}
	sort(a.begin(),a.end());
	vector<long long> t;
	rep(i,n)t.push_back(a[i][1]);
	t.push_back(0);
	sort(t.begin(),t.end());
	t.erase(unique(t.begin(),t.end()),t.end());
	
	segtree<long long,op,e> seg(t.size());
	{
		int d = distance(t.begin(),lower_bound(t.begin(),t.end(),0LL));
		seg.set(d,0);
	}
	bool f = false;
	rep(i,n){
		if(a[i][0]<0||a[i][1]<0)continue;
		int d = distance(t.begin(),lower_bound(t.begin(),t.end(),a[i][1]));
		long long v = seg.prod(0,d+1);
		v += a[i][2];
		seg.set(d,max(v,seg.get(d)));
	}
	cout<<seg.all_prod()<<endl;
	
	
	return 0;
}