//Was yea ra,rra yea ra synk sphilar yor en me exec hymme METAFALICA waath!
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2")
#include<bits/stdc++.h>
using namespace std;
#define rg register
#define ll long long
#define ull unsigned ll
#define lowbit(x) (x&(-x))
#define djq 998244353
const short sint=0x3f3f;
const int inf=0x3f3f3f3f;
const ll linf=0x3f3f3f3f3f3f3f3f;
const double alpha=0.73;
const double PI=acos(-1);
inline void file(){
	freopen("ball.in","r",stdin);
	freopen("ball.out","w",stdout);
}
char buf[1<<21],*p1=buf,*p2=buf;
inline int getc(){
    return p1==p2&&(p2=(p1=buf)+fread(buf,1,(1<<20)+5,stdin),p1==p2)?EOF:*p1++;
}
//#define getc getchar
inline ll read(){
	rg ll ret=0,f=0;char ch=getc();
    while(!isdigit(ch)){if(ch==EOF)exit(0);if(ch=='-')f=1;ch=getc();}
    while(isdigit(ch)){ret=ret*10+ch-48;ch=getc();}
    return f?-ret:ret;
}
inline int rdstr(char* s){
	char ch=getc(); int len(0);
	while(ch<33||ch>126) ch=getc();
	while(ch>=33&&ch<=126) (*s++)=ch,++len,ch=getc();
	return len;
}
#define ep emplace
#define epb emplace_back
#define all(x) (x).begin(),(x).end()
#define fi first
#define se second
#define it iterator
#define mkp make_pair
#define naive return 0*puts("Yes")
#define angry return 0*puts("No")
#define fls fflush(stdout)
#define rep(i,a) for(rg int i=1;i<=a;++i)
#define per(i,a) for(rg int i=a;i;--i)
#define rep0(i,a) for(rg int i=0;i<=a;++i)
#define per0(i,a) for(rg int i=a;~i;--i)
#define szf sizeof
typedef vector<int> vec;
typedef pair<int,int> pii;
struct point{ int x,y; point(int x=0,int y=0):x(x),y(y) {} inline bool operator<(const point& T)const{ return x^T.x?x<T.x:y<T.y; }; };
inline int ksm(int base,int p){int ret=1;while(p){if(p&1)ret=1ll*ret*base%djq;base=1ll*base*base%djq,p>>=1;}return ret;}
inline void pls(int& x,const int k){ x=(x+k>=djq?x+k-djq:x+k); }
inline int add(const int a,const int b){ return a+b>=djq?a+b-djq:a+b; }
inline void sub(int& x,const int k){ x=(x-k<0?x-k+djq:x-k); }
inline int inc(const int a,const int b){ return a<b?a-b+djq:a-b; }
inline void ckmn(int& x,const int k){ x=(k<x?k:x); }
inline void ckmx(int& x,const int k){ x=(k>x?k:x); }
inline void ckmn(ll& x,const ll k){ x=(k<x?k:x); }
inline void ckmx(ll& x,const ll k){ x=(k>x?k:x); }
mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());

#define double long double
const double eps=1e-16;
#define Vector Point
inline int dcmp(double a){return a<-eps?-1:(a>eps?1:0); }
inline double Abs(double a){return a*dcmp(a);}
double reps(){return (1.*(rnd()%98)/97-.5)*eps;}
struct Point{
	double x,y,z;
	void shake(){x+=reps(),y+=reps(),z+=reps();}	
	Point(double x=0,double y=0,double z=0):x(x),y(y),z(z) {}
}p[55];
inline Vector operator+(Vector a,Vector b){ return Vector(a.x+b.x,a.y+b.y,a.z+b.z); }
inline Vector operator-(Vector a,Vector b){ return Vector(a.x-b.x,a.y-b.y,a.z-b.z); }
inline Vector operator*(Vector a,double b){ return Vector(a.x*b,a.y*b,a.z*b); }
inline Vector operator/(Vector a,double b){ return Vector(a.x/b,a.y/b,a.z/b); }
inline double Dot(Point a,Point b){ return a.x*b.x+a.y*b.y+a.z*b.z; }
inline double Len(Point a){ return sqrt(Dot(a,a)); }
inline Point Cro(Point a,Point b){ return Point(a.y*b.z-a.z*b.y,a.z*b.x-a.x*b.z,a.x*b.y-a.y*b.x); }
struct face{
	int v[3];
	inline Point area(){ return Cro(p[v[1]]-p[v[0]],p[v[2]]-p[v[0]]); }
	inline bool check(int x){ return Dot(p[x]-p[v[0]],area())>0?1:0; }
};
int n;
bool flag,vis[2005][2005];
vector<face> cur; 
double ans;
inline void solve(){
	cur.clear();
	cur.push_back((face){1,2,3});
	cur.push_back((face){3,2,1});
	for(rg int i=4;i<=n;++i){
		vector<face> tmp;
		for(rg int j=0;j<cur.size();++j){
			face now=cur[j];
			int checker=now.check(i);
			if(!checker) tmp.epb(now);
			for(rg int k=0;k<3;++k){
				vis[now.v[k]][now.v[(k+1)%3]]=checker;
			}
		}
		for(rg int j=0;j<cur.size();++j){
			for(rg int k=0;k<3;++k){
				int now=cur[j].v[k],nex=cur[j].v[(k+1)%3];
				if(vis[now][nex]!=vis[nex][now]&&vis[now][nex]){
					tmp.push_back((face){now,nex,i});
				}
			}
		}
		cur=tmp;
	}
}
signed main(){
	//file();
	n=read();
	rep(i,n) p[i].x=read(),p[i].y=read(),p[i].z=read(),p[i].shake();
	solve(); double ans=1e9;
	for(rg int i=0;i<cur.size();++i){
		Point a=p[cur[i].v[0]],b=p[cur[i].v[1]],c=p[cur[i].v[2]];
		//printf("(%.3lf,%.3lf,%.3lf) (%.3lf,%.3lf,%.3lf) (%.3lf,%.3lf,%.3lf)\n",a.x,a.y,a.z,b.x,b.y,b.z,c.x,c.y,c.z);
		double ar=Len(Cro(b-a,c-a)),mx(0);
		rep(i,n){
			double nw=Dot(p[i]-a,Cro(b-a,c-a))/Len(Cro(b-a,c-a));
			mx=max(mx,fabs(nw));
		}
		ans=min(ans,mx);
	}
	printf("%.12Lf\n",ans);
	return 0;
}
/*

*/