// ConsoleApplication1.cpp: определяет точку входа для консольного приложения.
//


#include <iostream>
#include <cstdlib>
#include <cmath>
#include <iomanip>
#include <fstream>
#include <cstdio>

using namespace std;

typedef long double ld;
typedef long long ll;

struct tt {
	ld x, y, z, vx, vy, vz;
};

tt a[100010];
ll n;
ld eps = 1e-8;

ld mn(ld a, ld b)
{
	if (a - b > eps)
		return b;
	else
		return a;
}

ld mx(ld a, ld b)
{
	if (b - a > eps)
		return b;
	else
		return a;
}

ld f(ld t)
{
	ld mnx = 1e12, mxx = -1e12, mny = 1e12, mxy = -1e12, mnz = 1e12, mxz = -1e12;
	for (int i = 0; i < n; i++)
	{
		ld x = a[i].x + a[i].vx * t, y = a[i].y + a[i].vy * t, z = a[i].z + a[i].vz * t;
		mnx = mn(x, mnx);
		mny = mn(y, mny);
		mnz = mn(z, mnz);
		mxx = mx(x, mxx);
		mxy = mx(y, mxy);
		mxz = mx(z, mxz);
	}
	return mx(mxx - mnx, mx(mxy - mny, mxz - mnz));
}

int main()
{
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	cin >> n;
	for (int i = 0; i < n; i++)
		cin >> a[i].x >> a[i].y >> a[i].z >> a[i].vx >> a[i].vy >> a[i].vz;
	cout << setprecision(4) << fixed;
	ld l = 0, r = 1e10;
	while (r > l + eps)
	{
		double m = (r + l) / 2;

		if (f(m) > f(m + eps))
			l = m;
		else
			r = m;
	}
	cout << f(l) << endl;

    return 0;
}