#include <bits/stdc++.h>
#define ll long long
#define pb push_back

using namespace std;

int main()
{
    ios_base::sync_with_stdio(false);
	cin.tie(nullptr);
	cout.tie(nullptr);
	cout << fixed << setprecision(13);

    int n;
    cin >> n;
    vector<double> x(n), y(n), z(n);

    for(int i=0; i<n; i++) cin >> x[i] >> y[i] >> z[i];

    double ans = 10000;
    for(int i=0; i<n; i++)
    {
        for(int j=i+1; j<n; j++)
        {
            double v1_x = x[i]-x[j], v1_y = y[i]-y[j], v1_z = z[i]-z[j];

            for(int k=j+1; k<n; k++)
            {
                double v2_x = x[i]-x[k], v2_y = y[i]-y[k], v2_z = z[i]-z[k];
                double v1xv2_x = v1_y*v2_z-v2_y*v1_z, v1xv2_y = v1_z*v2_x-v2_z*v1_x, v1xv2_z = v1_x*v2_y-v2_x*v1_y;
                double len = sqrt(v1xv2_x*v1xv2_x + v1xv2_y*v1xv2_y + v1xv2_z*v1xv2_z);
                double M = 0, m = 0;

                for(int l=0; l<n; l++)
                {
                    //cout << i << j << k << l << " " << ((x[l]-x[i])*v1xv2_x + (y[l]-y[i])*v1xv2_y + (z[l]-z[i])*v1xv2_z)/len << "\n";
                    M = max(M, ((x[l]-x[i])*v1xv2_x + (y[l]-y[i])*v1xv2_y + (z[l]-z[i])*v1xv2_z)/len);
                    m = min(m, ((x[l]-x[i])*v1xv2_x + (y[l]-y[i])*v1xv2_y + (z[l]-z[i])*v1xv2_z)/len);
                }

                ans = min(ans, M - m);
            }
        }
    }

    cout << ans;
}