#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
#define y1 y114514
int n,x[51],y[51],z[51];
ld ans=1e15;
bool flag;
int main(){
	cin>>n;
	for(int i=1;i<=n;i++)cin>>x[i]>>y[i]>>z[i];
	for(int i=1;i<=n;i++){
		for(int j=1;j<=n;j++){
			for(int k=1;k<=n;k++){
				ll x1=x[i],y1=y[i],z1=z[i],x2=x[j],y2=y[j],z2=z[j],x3=x[k],y3=y[k],z3=z[k];
				ll xa=x2-x1,ya=y2-y1,za=z2-z1,xb=x3-x1,yb=y3-y1,zb=z3-z1;
				ll a=ya*zb-yb*za;
				ll b=za*xb-xa*zb;
				ll c=xa*yb-ya*xb;
				if(a==0&&b==0&&c==0)continue;
				flag=1;
				ll d=a*x1+b*y1+c*z1;
				d=-d;
				ld mx=-1e15,mi=1e15;
				for(int l=1;l<=n;l++){
					ld tmp=a*x[l]+b*y[l]+c*z[l]+d;
					ld p=a*a+b*b+c*c;p=sqrt(p);
					tmp/=p;
					mx=max(mx,tmp),mi=min(mi,tmp);
				}
				ans=min(ans,mx-mi);
			}
		}
	}
	if(!flag)puts("0");
	else printf("%.12Lf",ans);
}