#include <algorithm>
#include <cmath>
#include <iomanip>
#include <iostream>
#include <vector>

using namespace std;

int main() {
	int n;
	cin >> n;

    vector<long long> xs, ys, zs;

	for (int i = 0; i < n; i++) {
		long long x, y, z;
		cin >> x >> y >> z;
        xs.push_back(x);
        ys.push_back(y);
        zs.push_back(z);
	}

	long double ans = 1e12;
	for (int i = 0; i < n; i++) {
        for (int j = i + 1; j < n; j++) {
            ans = min(ans, sqrt((long double)
                (xs[i]-xs[j])*(xs[i]-xs[j]) +
                (ys[i]-ys[j])*(ys[i]-ys[j]) +
                (zs[i]-zs[j])*(zs[i]-zs[j])
            ));
        }
	}

	cout << fixed << setprecision(20) << ans << endl;
}