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

typedef long long db;
int sign(db k){
    if (k>0) return 1;
    else if (k<0) return -1;
    return 0;
}
int cmp(db k1,db k2){
    return sign(k1-k2);
}
struct point{
    db x,y;
    point operator + (const point &k1) const{return (point){x+k1.x,y+k1.y};}
    point operator - (const point &k1) const{return (point){x-k1.x,y-k1.y};}
    point operator * (db k1) const{return (point){x*k1,y*k1};}
    point operator / (db k1) const{return (point){x*k1,y*k1};}
    friend ostream& operator << (ostream &os,const point &k){
        os << "(" << k.x << "," << k.y << ")";
        return os;
    }
};

db cross(point k1,point k2){return k1.x*k2.y-k1.y*k2.x;}
db dot(point k1,point k2){return k1.x*k2.x+k1.y*k2.y;}

typedef long long ll;
const int maxn=2000;
ll n;
pair<point,point> a[maxn+50];

signed main(){
    ios_base::sync_with_stdio(false);
    cin >> n;
    for (int i=1;i<=n;i++){
        long long x1,x2,y;
        cin >> x1 >> x2 >> y;
        if (x1>x2) swap(x1,x2); 
        a[i].first=(point){(db)x1,(db)y};
        a[i].second=(point){(db)x2,(db)y};
    }

    ll ans=0;
    for (int sel=1;sel<=n;sel++){
    //    cerr << "sel : " << sel << endl;
        ll Olen=a[sel].second.x-a[sel].first.x;
        ans=max(ans,Olen);
        auto gao=[&](point O){
        //    cerr << "--------gao---------------" << endl;
        //    cerr << "O : " << O << endl;
            vector<pair<point,ll>> vup;
            vector<pair<point,ll>> vdown;
            vector<point> dir;
            for (int j=1;j<=n;j++){
                if (a[j].first.y==O.y) continue;
                ll len=a[j].second.x-a[j].first.x;
                if (a[j].first.y>O.y){
                    dir.emplace_back(a[j].first-O);
                    dir.emplace_back(a[j].second-O);
                    vup.emplace_back(a[j].first-O,-len);
                    vup.emplace_back(a[j].second-O,+len);
                }
                else{
                    dir.emplace_back(O-a[j].first);
                    dir.emplace_back(O-a[j].second);
                    vdown.emplace_back(a[j].first-O,+len);
                    vdown.emplace_back(a[j].second-O,-len);
                }
            }
            auto cmp = [&](const pair<point,ll> &X,const pair<point,ll> &Y){
                int flag=sign(cross(X.first,Y.first));
                if (flag!=0) return flag==1;
                return X.second>Y.second;
            };
            sort(vup.begin(),vup.end(),cmp);
            sort(vdown.begin(),vdown.end(),cmp);

        //    cerr << "vup : " << endl;
         //   for (auto [X,Y]:vup) cerr << X << " " << Y << endl;
         //   cerr << "vdown : " << endl;
         //   for (auto [X,Y]:vdown) cerr << X << " " << Y << endl;

            vector<ll> sumup(vup.size()+1);
            if (vup.size()) sumup[0]=vup[0].second;
            for (int i=1;i<(int)vup.size();i++) sumup[i]=sumup[i-1]+vup[i].second;

            vector<ll> sumdown(vdown.size()+1);
            if (vdown.size()) sumdown[0]=vdown[0].second;
            for (int i=1;i<(int)vdown.size();i++) sumdown[i]=sumdown[i-1]+vdown[i].second;

            for (auto d:dir){
            //    cerr << "d : " << d << endl;
                ll sum=Olen;
                if (vup.size()){
                    int posup=upper_bound(vup.begin(),vup.end(),make_pair(d,0LL),cmp)-vup.begin()-1;
                    if (posup>=0) sum+=sumup[posup];
                //    cerr << "sum1 : " << sum << endl;
                }
                if (vdown.size()){
                    point revd=d*(-1);
                    int posdown=upper_bound(vdown.begin(),vdown.end(),make_pair(revd,0LL),cmp)-vdown.begin()-1;
                    if (posdown>=0)sum+=sumdown[posdown];
                }
            //   cerr << "sum : " << sum << endl;
                ans=max(ans,sum);
            }
        };
        gao(a[sel].first);
        gao(a[sel].second);
    }
    cout << ans << "\n";
    return 0;
}