#include<bits/stdc++.h>
using namespace std;
using ll = long long;

#include<atcoder/segtree>

ll op(ll a,ll b){
    return max(a,b);
}
ll e(){
    return -1e18;
}

int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    
    int n;
    cin>>n;
    vector<ll> dx;
    vector<ll> t(n),x(n),v(n);
    for(int i = 0;i<n;i++){
        cin>>t[i]>>x[i]>>v[i];
        dx.push_back(t[i]-x[i]);
        dx.push_back(x[i]+t[i]);
    }
    dx.push_back(0);
    vector<int> idx(n);
    for(int i = 0;i<n;i++) idx[i] = i;
    sort(dx.begin(),dx.end());
    dx.erase(unique(dx.begin(),dx.end()),dx.end());
    sort(idx.begin(),idx.end(),[&](int i,int j){
        if(t[i]+x[i]==t[j]+x[j]) return t[i] - x[i] < t[j] - x[j];
        return t[i] + x[i] < t[j] + x[j];});
    ll ans = 0;
    int m = dx.size();
    atcoder::segtree<ll,op,e> seg(m);
    int nk = lower_bound(dx.begin(),dx.end(),0) - dx.begin();
    for(int i = 0;i<n;i++){
        int ni = idx[i];
        int nni = lower_bound(dx.begin(),dx.end(),t[ni]-x[ni]) - dx.begin();
        ll now = seg.prod(0,nni+1) + v[ni];
        if(-t[ni]<=x[ni]&&x[ni]<=t[ni]) now = op(now,v[ni]);
        seg.set(nni,op(seg.get(nni),now));
        ans = max(ans,now);
    }
    cout<<ans<<endl;
    
}