#include<bits/stdc++.h>
using namespace std;
namespace IO{
	template<typename T>inline bool read(T &x){
		x=0;
		char ch=getchar();
		bool flag=0,ret=0;
		while(ch<'0'||ch>'9') flag=flag||(ch=='-'),ch=getchar();
		while(ch>='0'&&ch<='9') x=x*10+ch-'0',ch=getchar(),ret=1;
		x=flag?-x:x;
        return ret;
	}
	template<typename T,typename ...Args>inline bool read(T& a,Args& ...args){
	    return read(a)&&read(args...);
	}
	template<typename T>void prt(T x){
		if(x>9) prt(x/10);
		putchar(x%10+'0');
	}
	template<typename T>inline void put(T x){
		if(x<0) putchar('-'),x=-x;
		prt(x);
	}
	template<typename T>inline void put(char ch,T x){
		if(x<0) putchar('-'),x=-x;
		prt(x);
		putchar(ch);
	}
	template<typename T,typename ...Args>inline void put(T a,Args ...args){
	    put(a);
		put(args...);
	}
	template<typename T,typename ...Args>inline void put(const char ch,T a,Args ...args){
	    put(ch,a);
		put(ch,args...);
	}
	inline void put(string s){
		for(int i=0,sz=s.length();i<sz;i++) putchar(s[i]);
	}
	inline void put(const char* s){
		for(int i=0,sz=strlen(s);i<sz;i++) putchar(s[i]);
	}
}
using namespace IO;
#define N 4005 
#define ll long long
struct Line{
	int l,r,h;
}p[N];
inline int check(ll x){
	if(x<0) return -1;
	if(x==0) return 0;
	if(x>0) return 1;
}
struct node{
	int dx,dy,id;
	node(int _dx=0,int _dy=0,int _id=0):dx(_dx),dy(_dy),id(_id){}
	inline bool operator<(const node &b)const{
		return (long double)dy/dx<(long double)b.dy/b.dx;
//		if(check((ll)dx*b.dx)!=check((ll)dy*b.dy)) return check((ll)dx*b.dx)<check((ll)dy*b.dy);
//		return (ll)dy*b.dx<(ll)b.dy*dx;
	}
	inline bool operator==(const node &b)const{
		return (ll)dx*b.dy==(ll)dy*b.dx;
	}
}t[N];
int n,vis[N];
ll ans;
inline ll solve(int x,int y){
	memset(vis,0,sizeof(vis));
	ll res=0;int m=0;
	for(int i=1;i<=n;i++){
		if(p[i].h==y) continue;
		t[++m]=node(p[i].h-y,p[i].l-x,i);
		t[++m]=node(p[i].h-y,p[i].r-x,i);
	}
	
	sort(t+1,t+m+1);
	ll val=0;
	for(int i=1;i<=m;){
		int j=i;ll del=0;
		if(!vis[t[j].id]) val+=p[t[j].id].r-p[t[j].id].l,vis[t[j].id]=1; 
		else del+=p[t[j].id].r-p[t[j].id].l;
		while(j+1<=m&&t[j]==t[j+1]){
			j++;
			if(!vis[t[j].id]) val+=p[t[j].id].r-p[t[j].id].l,vis[t[j].id]=1; 
			else del+=p[t[j].id].r-p[t[j].id].l;
		}
		res=max(res,val),val-=del;
		i=j+1;
	}
	return res;
}
int main(){
	read(n);
	for(int i=1;i<=n;i++){
		read(p[i].l,p[i].r,p[i].h);
		if(p[i].l>p[i].r) swap(p[i].l,p[i].r);
	}
	for(int i=1;i<=n;i++)
		ans=max(ans,p[i].r-p[i].l+max(solve(p[i].l,p[i].h),solve(p[i].r,p[i].h)));
	put('\n',ans);	
	return 0;
}