#include <iostream>
#include <string>
#include <algorithm>
#include <iomanip>
#include <vector>
#include <map>
#include <cmath>
#include <queue>
#include <utility>
#include <functional>
#include <deque>
#include <cctype>
#include <stack>
#include <bitset>
#include <set>

using ll = long long;
using namespace std;
typedef unsigned long long ull;
typedef pair<ll, ll> P;

const ll MOD = 1000000007;
const ll INF = 1 << 30;
const ll INF2 = 9000000000000000000LL;
const double INF3 = 900000000000000;
const int dx[4] = { 1,0,-1,0 }, dy[4] = { 0,1,0,-1 };
const int tx[8] = { -1,0,1,-1,1,-1,0,1 }, ty[8] = { -1,-1,-1,0,0,1,1,1 };
#define ALL(x) (x).begin(),(x).end()

ll par[100010], Rank[100010];

void init(int n) {
	for (int i = 0;i < n;i++)par[i] = i, Rank[i] = 0;
}
int find(ll x) {
	if (par[x] == x)return x;
	else return par[x] = find(par[x]);
}
void unite(ll x, ll y) {
	x = find(x);
	y = find(y);
	if (x == y)return;
	if (Rank[x] < Rank[y])par[x] = y;
	else {
		par[y] = x;
		if (Rank[x] == Rank[y])Rank[x]++;
	}
}
bool same(ll x, ll y) {
	return find(x) == find(y);
}


int main() {
	ll n, x[1010], y[1010], ans = INF2;
	cin >> n;
	for (int i = 0;i < n;i++) {
		cin >> x[i] >> y[i];
	}
	vector<pair<ll, P>>v;
	for (int i = 0;i < n - 1;i++)for (int j = i + 1;j < n;j++) {
		ll dis = (ll)sqrt((x[i] - x[j]) * (x[i] - x[j]) + (y[i] - y[j]) * (y[i] - y[j]));
		dis -= dis % 10;
		while (dis*dis < (x[i] - x[j]) * (x[i] - x[j]) + (y[i] - y[j]) * (y[i] - y[j]))dis += 10;
		v.push_back(make_pair(dis, make_pair(i, j)));
	}
	sort(v.begin(), v.end());
	init(1010);
	for (int i = 0;i < v.size();i++) {
		if (!same(v[i].second.first, v[i].second.second)) {
			unite(v[i].second.first, v[i].second.second);
			ans = v[i].first;
		}
		if (find(0) == find(n - 1))break;
	}
	cout << ans << endl;
}