#include <iostream>
#include <algorithm>
#include <cmath>
#include <iomanip>

using namespace std;

typedef long long ll;

const int maxn = 2100;

struct point{
    ll x,y;
    int dir; //-1 for left, 1 for right
    int id;
};

ll x0[maxn],x1[maxn],y[maxn];
point p[maxn << 1];
int events[maxn << 1];

point base;

int sign_line(point base,point p){
  if ((p.y > base.y && p.dir == 1)
  || (p.y < base.y && p.dir == -1)) return 1;
  else return -1;
}
bool comp(int a,int b){
    // priority goes to "+"
    if ((p[a].x - base.x) *  (p[b].y - base.y)
      != (p[b].x - base.x) * (p[a].y - base.y))
       return
       (p[a].x - base.x) *  (p[b].y - base.y)
         > (p[b].x - base.x) * (p[a].y - base.y);
    int signa = sign_line(base, p[a]);
    int signb = sign_line(base, p[b]);
    return signa > signb;
}



int main(){
    int n;
    cin >> n;
    for (int i = 1;i <= n;i++){
        cin >> x0[i] >> x1[i] >> y[i];
        y[i] *= -1;
        if (x0[i] > x1[i]) swap(x0[i],x1[i]);
        p[2*i-1] = (point){x0[i], y[i], -1, i};
        p[2*i] = (point){x1[i], y[i], 1, i};
    }
    ll ret = 0;
    for (int i = 1;i <= 2*n;i++){
        int siz = 0;
      //  printf("i = %d\n",i);
        for (int j = 1;j <= 2*n;j++){
            if (j == i) continue;
            if (p[j].y == p[i].y) continue;
            events[++siz] = j;
        }
        base = p[i];
        sort(events+1,events+siz+1,comp);
        ll cur = x1[p[i].id] - x0[p[i].id];
        ret = max(ret, cur);
        for (int j = 1;j <= siz;j++){
          point pt = p[events[j]];
      //    printf("Event: point (%lld,%lld) with sign %d; cur = %lld\n", pt.x, pt.y, sign_line(base,pt), cur);
          cur +=  sign_line(base, pt) * (x1[pt.id] - x0[pt.id]);
          ret = max(ret, cur);
        }
    }
    cout << ret << endl;
}