#include <bits/stdc++.h>
#define x first
#define y second
using namespace std;
using ll=long long;
using ld=long double;
using pii=pair<int,int>;
using vi=vector<int>;
using vl=vector<ll>;
#define pb push_back
#define all(a) begin(a),end(a)

template<class T> int sgn(T x) {return (x>0)-(x<0);}
template<class T>
struct Point {
	typedef Point P;
	T x,y;
	explicit Point(T x=0,T y=0) : x(x), y(y) {}
	bool operator<(P p) const {return tie(x,y)<tie(p.x,p.y);}
	bool operator==(P p) const {return tie(x,y)==tie(p.x,p.y);}
	P operator+(P p) const {return P(x+p.x,y+p.y);}
	P operator-(P p) const {return P(x-p.x,y-p.y);}
	P operator*(T d) const {return P(x*d,y*d);}
	P operator/(T d) const {return P(x/d,y/d);}
	T dot(P p) const {return x*p.x+y*p.y;}
	T cross(P p) const {return x*p.y-y*p.x;}
	T cross(P a,P b) const {return (a-*this).cross(b-*this);}
	T dist2() const {return x*x+y*y;}
	ld dist() const {return sqrt((ld)dist2());}
	ld angle() const {return atan2(y,x);}
	P unit() const {return *this/dist();}
	P perp() const {return P(-y,x);}
	P normal() const {return perp().unit();}
	P rotate(double a) const {return P(x*cos(a)-y*sin(a),x*sin(a)+y*cos(a));}
	friend ostream& operator<<(ostream&os,P p) {
		return os << "(" << p.x << "," << p.y << ")";
	}
};

typedef Point<ld> P;
P lt(const P&p0,const P&p1,const P&q0,const P&q1,const P&r)
{
	P dp=p1-p0,dq=q1-q0,num(dp.cross(dq),dp.dot(dq));
	return q0+P((r-p0).cross(num),(r-p0).dot(num))/dp.dist2();
}

const int N=410,MOD=1e9+7,M=1<<9;
const char en='\n';
const ll LLINF=1ll<<60;
const ld eps=1e-8; //per se poveca za najvise eps

int n;
pair<ld,ld> seg[2][M*2+10];
pair<P,int> h[N];
ld cuan;

pair<ld,ld> mer(pair<ld,ld> a,pair<ld,ld> b)
{
	return {a.x+b.x,max(a.y,a.x+b.y)};
}

void upd(int i,int j,ld x)
{
	seg[j][i+=M].x+=x;
	seg[j][i].y=max(0.L,seg[j][i].x);
	for (i/=2;i;i/=2) seg[j][i]=mer(seg[j][i*2],seg[j][i*2+1]);
}

pair<ld,ld> ge(int l,int r,int j,int lo=0,int hi=M,int i=1)
{
	if (lo>=l && hi<=r) return seg[j][i];
	if (lo>=r || hi<=l) return {0,0};
	int mid=(lo+hi)/2;
	return mer(ge(l,r,j,lo,mid,i*2),ge(l,r,j,mid,hi,i*2+1));
}

int main()
{
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cin>>n;
	ld ma=0;
	for (int i=0;i<n;++i)
	{
		cin>>h[i].x.x>>h[i].x.y>>h[i].y;
		ma=max(ma,ld(h[i].y));
	}
	for (int i=0;i<n;++i) for (int j=i+1;j<n;++j)
	{
		vector<pair<pair<ld,ld>,int>> vec,man;
		vector<ld> vxman,vxvec;
		P p0=h[i].x,p1=h[j].x,q0=P(0,0),q1=P((h[i].x-h[j].x).dist(),0);
		for (int k=0;k<n;++k)
		{
			P nov=lt(p0,p1,q0,q1,h[k].x);
			if (nov.x<0) vxman.pb(-nov.x);
			if (nov.x>q1.x) vxvec.pb(nov.x-q1.x);
			if (nov.y>-eps) vec.pb({{nov.y,nov.x},h[k].y});
			if (nov.y<eps) man.pb({{-nov.y,nov.x},h[k].y});
		}
		sort(all(vec));
		sort(all(man));
		sort(all(vxman));
		vxman.erase(unique(all(vxman)),vxman.end());
		sort(all(vxvec));
		vxvec.erase(unique(all(vxvec)),vxvec.end());
		//clear starts
		for (int i=0;i<2*M;++i) seg[0][i]=seg[1][i]={0,0};
		cuan=-2*q1.x;
		for (int i=0;i<(int)vxman.size();++i)
		{
			ld dif=vxman[i];
			if (i) dif-=vxman[i-1];
			upd(i,0,-2*dif);
		}
		for (int i=0;i<(int)vxvec.size();++i)
		{
			ld dif=vxvec[i];
			if (i) dif-=vxvec[i-1];
			upd(i,1,-2*dif);
		}
		//clear ends
		for (auto x: vec)
		{
			if (x.x.y<0)
			{
				upd(lower_bound(all(vxman),-x.x.y)-vxman.begin(),0,x.y);
			}
			else if (x.x.y>q1.x)
			{
				upd(lower_bound(all(vxvec),x.x.y-q1.x)-vxvec.begin(),1,x.y);
			}
			else cuan+=x.y;
			ma=max(ma,cuan-2*x.x.x+seg[0][1].y+seg[1][1].y);
		}
		//clear starts
		for (int i=0;i<2*M;++i) seg[0][i]=seg[1][i]={0,0};
		cuan=-2*q1.x;
		for (int i=0;i<(int)vxman.size();++i)
		{
			ld dif=vxman[i];
			if (i) dif-=vxman[i-1];
			upd(i,0,-2*dif);
		}
		for (int i=0;i<(int)vxvec.size();++i)
		{
			ld dif=vxvec[i];
			if (i) dif-=vxvec[i-1];
			upd(i,1,-2*dif);
		}
		//clear ends
		for (auto x: man)
		{
			if (x.x.y<0)
			{
				upd(lower_bound(all(vxman),-x.x.y)-vxman.begin(),0,x.y);
			}
			else if (x.x.y>q1.x)
			{
				upd(lower_bound(all(vxvec),x.x.y-q1.x)-vxvec.begin(),1,x.y);
			}
			else cuan+=x.y;
			ma=max(ma,cuan-2*x.x.x+seg[0][1].y+seg[1][1].y);
		}
	}
	cout<<fixed<<setprecision(10)<<ma<<en;
}