#include<bits/stdc++.h>
using namespace std;
const int N=2010;
int n,val[2*N],tot,ans;
struct Point
{
    int x,y;
    friend inline Point operator + (const Point &a,const Point &b) {return (Point){a.x+b.x,a.y+b.y};}
    friend inline Point operator - (const Point &a,const Point &b) {return (Point){a.x-b.x,a.y-b.y};}
    friend inline int operator * (const Point &a,const Point &b) {return a.x*b.y-a.y*b.x;}
    friend inline bool operator == (const Point &a,const Point &b) {return (a.x==b.x)&(a.y==b.y);}
};
struct Line
{
    Point a,b;
};
struct node
{
    Point p;
    int val;
}b[2*N];
Line a[N];
Point base;

int sign(Point x)
{
    if(x.y>0 || (x.y==0 && x.x>0)) return 0;
    return 1;
}

bool cmp(node a,node b)
{
    if(sign(a.p)!=sign(b.p)) return sign(a.p)<sign(b.p);
    return a.p*b.p>=0;
}

int work(Point x)
{
    base=x;
    tot=0;
    int sum=0,res=0;
    for(int i=1;i<=n;i++) 
    {
        if(a[i].a==x || a[i].b==x) {sum+=a[i].b.x-a[i].a.x;continue;}
        if(a[i].a.y<x.y) b[++tot]={a[i].a-base,(a[i].b.x-a[i].a.x)},b[++tot]={a[i].b-base,-(a[i].b.x-a[i].a.x)};
        else b[++tot]={a[i].b-base,(a[i].b.x-a[i].a.x)},b[++tot]={a[i].a-base,-(a[i].b.x-a[i].a.x)};
    }
    sort(b+1,b+tot+1,cmp);
    for(int i=1;i<=tot;i++) sum+=b[i].val,res=max(res,sum);
    return res;
}

int main(void)
{
    scanf("%d",&n);
    for(int i=1,x0,x1,y;i<=n;i++)
    {
        scanf("%d%d%d",&x0,&x1,&y);
        if(x0>x1) swap(x0,x1);
        a[i]=(Line){(Point){x0,y},(Point){x1,y}};
    }
    for(int i=1;i<=n;i++) ans=max({ans,work(a[i].a),work(a[i].b)});
    
    printf("%d\n",ans);
    
    return 0;
}