#include<bits/stdc++.h>
#define ll long long
#define ull unsigned long long
#define int ll
#define fr first
#define se second
#define INF 0x3f3f3f3f
#define LINF 0x3f3f3f3f3f3f3f3f
#define all(x) x.begin(),x.end()
#define For(i,a,b) for(int i = a; i <= b; ++i)
#define Rep(i,a,b) for(int i = a; i >= b; --i)
using namespace std;
typedef pair<int,int> pii;
#ifdef OVAL
const int N = 2e3+10;
#else
const int N = 2e5+10;
#endif
#define eps 1e-8
#define zero(x) (((x)>0?(x):-(x))<eps)
struct point3{double x,y,z;};
struct line3{point3 a,b;};
struct plane3{point3 a,b,c;};
typedef point3 P;
point3 xmult(point3 u,point3 v){//叉乘
	point3 ret;
	ret.x=u.y*v.z-v.y*u.z;
	ret.y=u.z*v.x-u.x*v.z;
	ret.z=u.x*v.y-u.y*v.x;
	return ret;
}
//计算 dot product product product product U . V
double dmult(point3 u,point3 v){
	return u.x*v.x+u.y*v.y+u.z*v.z;
}
//矢量差 U - V
point3 subt(point3 u,point3 v){
	point3 ret;
	ret.x=u.x-v.x;
	ret.y=u.y-v.y;
	ret.z=u.z-v.z;
	return ret;
}
//取法向量
point3 pvec(plane3 s){
	return xmult(subt(s.a,s.b),subt(s.b,s.c));
}
point3 pvec(point3 s1,point3 s2,point3 s3){
	return xmult(subt(s1,s2),subt(s2,s3));
}
point3 intersection(point3 l1,point3 l2,point3 s1,point3 s2,point3 s3){
	point3 ret=pvec(s1,s2,s3);
	double t=(ret.x*(s1.x-l1.x)+ret.y*(s1.y-l1.y)+ret.z*(s1.z-l1.z))/
	(ret.x*(l2.x-l1.x)+ret.y*(l2.y-l1.y)+ret.z*(l2.z-l1.z));
	ret.x=l1.x+(l2.x-l1.x)*t;
	ret.y=l1.y+(l2.y-l1.y)*t;
	ret.z=l1.z+(l2.z-l1.z)*t;
	return ret;
}
double vlen(point3 p){
	return sqrt(p.x*p.x+p.y*p.y+p.z*p.z);
}
P unit(P p){
	double len = vlen(p);
	return {p.x/len, p.y/len, p.z/len};
}
int dots_inline(point3 p1,point3 p2,point3 p3){
	return vlen(xmult(subt(p1,p2),subt(p2,p3)))<eps;
}
//直线平行
int parallel(line3 u,line3 v){
return vlen(xmult(subt(u.a,u.b),subt(v.a,v.b)))<eps;
}
int parallel(point3 u1,point3 u2,point3 v1,point3 v2){
return vlen(xmult(subt(u1,u2),subt(v1,v2)))<eps;
}
//平面平行
int parallel(plane3 u,plane3 v){
	return vlen(xmult(pvec(u),pvec(v)))<eps;
}
int parallel(point3 u1,point3 u2,point3 u3,point3 v1,point3 v2,point3 v3){
	return vlen(xmult(pvec(u1,u2,u3),pvec(v1,v2,v3)))<eps;
}
//线面平行
int parallel(line3 l,plane3 s){
	return zero(dmult(subt(l.a,l.b),pvec(s)));
}
int parallel(point3 l1,point3 l2,point3 s1,point3 s2,point3 s3){
	return zero(dmult(subt(l1,l2),pvec(s1,s2,s3)));
}

double ptoplane(point3 p,plane3 s){
	return fabs(dmult(pvec(s),subt(p,s.a)))/vlen(pvec(s));
}
double ptoplane(point3 p,point3 s1,point3 s2,point3 s3){
	return fabs(dmult(pvec(s1,s2,s3),subt(p,s1)))/vlen(pvec(s1,s2,s3));
}
int n;
P ps[N];
void solve()
{
	cin >> n;
	For(i,1,n){
		cin >> ps[i].x >> ps[i].y >> ps[i].z;
	}
	double ans = 1e99;
	For(i,1,n)For(j,i+1,n){
		P vec1 = subt(ps[i], ps[j]);
		For(k,1,n)For(l,k+1,n){
			P vec2 = subt(ps[k], ps[l]);
			P fa = xmult(vec1, vec2);
			if(fabsl(vlen(fa)) < eps)continue;
			fa = unit(fa);
			double mx = -1e99, mn = 1e99;
			For(w,1,n){
				double ds = dmult(fa, ps[w]);
				mx = max(mx, ds);
				mn = min(mn, ds);
			}
			ans = min(ans, mx-mn);
		}
	}
	cout << ans << '\n';
}
signed main()
{
	ios::sync_with_stdio(false),cin.tie(0),cout.tie(0);
	// freopen("in.txt", "r", stdin);
	// freopen("out.txt", "w", stdout);
	int tt = 1;
	cout << fixed << setprecision(12);
	// cin >> tt;
	For(tc,1,tt){
		solve();
	}
	return 0;
}