#include<bits/stdc++.h>
#define fi first
#define se second
#define eb emplace_back
#define mp make_pair
using namespace std;
typedef long double ld;
typedef long long ll;
typedef unsigned long long ull;
typedef __int128 i128; 
template<typename T,typename U>
T ceil(T x, U y) {return (x>0?(x+y-1)/y:x/y);}
template<typename T,typename U>
T floor(T x, U y) {return (x>0?x/y:(x-y+1)/y);}
template<class T,class S>
bool chmax(T &a,const S b) {return (a<b?a=b,1:0);}
template<class T,class S>
bool chmin(T &a,const S b) {return (a>b?a=b,1:0);}
int popcnt(int x) {return __builtin_popcount(x);}
int popcnt(ll x)  {return __builtin_popcountll(x);}
int topbit(int x) {return (x==0?-1:31-__builtin_clz(x));}
int topbit(ll x)  {return (x==0?-1:63-__builtin_clzll(x));}
int lowbit(int x) {return (x==0?-1:__builtin_ctz(x));}
int lowbit(ll x)  {return (x==0?-1:__builtin_ctzll(x));}

#define int long long
#define rep(i,a,b) for(int i=(a);i<=(b);i++)
#define per(i,a,b) for(int i=(a);i>=(b);i--)
typedef pair<int,int> pii; 
typedef vector<int> vi;
typedef vector<pii> vp;
typedef tuple<int,int,int> tiii;
int read() {
  int x=0,w=1; char c=getchar(); 
  while(!isdigit(c)) {if(c=='-') w=-1; c=getchar();}
  while(isdigit(c)) {x=x*10+(c-'0'); c=getchar();}
  return x*w;
}

const int N=2005;
int n,P[N],Q[N],tot,ans;
struct node {int x,y,w;} a[N];
bool cmpy(node &x,node &y) {return x.y==y.y?x.x<y.x:x.y>y.y;}
struct slp {int i,j,dx,dy;} b[N*N];
slp get_slope(int i,int j) { //yi>yj, xi>xj
  slp b; b.i=i, b.j=j;
  b.dy=a[i].y-a[j].y, b.dx=a[i].x-a[j].x;
  return b;
}
bool cmps(slp &a,slp &b) {
  return a.dy*b.dx<b.dy*a.dx;
}
bool eq(slp &a,slp &b) {
  return a.dy*b.dx==b.dy*a.dx;
}

namespace SegT {
  struct node {
    int l,r,s,c;
    node(int a=0) {s=a,l=r=c=max(a,0ll);}
  };
  node operator + (const node &a,const node &b) {
    node c;
    c.l=max(a.l,a.s+b.l);
    c.r=max(b.r,b.s+a.r);
    c.s=a.s+b.s;
    c.c=max(max(a.c,b.c),a.r+b.l);
    return c;
  }
  int ls[N<<1],rs[N<<1],tot=1; node s[N<<1];
  void init() {
    rep(i,1,tot) ls[i]=rs[i]=0, s[i]=node(0);
    tot=1;
  }
  void build(int p,int l,int r) {
    if(l==r) {s[p]=node(a[l].w); return;} int mid=l+r>>1;
    build(ls[p]=++tot,l,mid), build(rs[p]=++tot,mid+1,r);
    s[p]=s[ls[p]]+s[rs[p]];
  }
  void mdf(int p,int l,int r,int x,int y) {
    if(l==r) {s[p]=node(y); return;} int mid=l+r>>1;
    if(x<=mid) mdf(ls[p],l,mid,x,y); else mdf(rs[p],mid+1,r,x,y);
    s[p]=s[ls[p]]+s[rs[p]];
  }
  int qry() {return s[1].c;}
}

void work() {
  sort(a+1,a+n+1,cmpy); tot=0;
  rep(i,1,n) rep(j,i+1,n) if(a[i].y>a[j].y&&a[i].x>a[j].x) b[++tot]=get_slope(i,j);
  sort(b+1,b+tot+1,cmps);
  SegT::init(); SegT::build(1,1,n);
  rep(i,1,n) P[i]=Q[i]=i;
  rep(i,1,tot) {
    int p=i; vi e;
    for(;i<=tot&&eq(b[p],b[i]);i++) {
      if(Q[b[i].i]+1==Q[b[i].j]) {
        e.eb(Q[b[i].i]);
      }
    } i--;
    sort(e.begin(),e.end()); int sz=e.size();
    chmax(ans,SegT::qry());
    rep(j,0,sz-1) {
      int k=j+1;
      for(;k<sz&&e[k]==e[k-1]+1;k++); k--;
      reverse(P+e[j],P+e[k]+2);
      rep(x,e[j],e[k]+1) Q[P[x]]=x;
      rep(x,e[j],e[k]+1) SegT::mdf(1,1,n,x,a[P[x]].w);
      j=k;
    }
  }
}
void wory() {
  int sum=0; sort(a+1,a+n+1,cmpy);
  rep(i,1,n) chmax(ans,sum), sum=max(sum,0ll)+a[i].w;
  chmax(ans,sum);
}

signed main() {
  n=read();
  rep(i,1,n) a[i].x=read(), a[i].y=read(), a[i].w=read();
  work();
  rep(i,1,n) a[i].x=-a[i].x;
  work();
  wory();
  rep(i,1,n) a[i].x=-a[i].x;
  wory();
  rep(i,1,n) swap(a[i].x,a[i].y);
  wory();
  rep(i,1,n) a[i].x=-a[i].x;
  wory();
  printf("%lld\n",ans);
  return 0;
}