#include <cassert>
#include <functional>
#include <set>
#include <ctime>
#include <cmath>
#include <climits>
#include <cstring>
#include <string>
#include <queue>
#include <map>
#include <vector>
#include <algorithm>
#include <iostream>
#include <cstdio>
#ifndef ONLINE_JUDGE //POJ
# include <random>
# include <array>
# define mkt make_tuple
# define empb emplace_back
#endif
#ifdef _LOCAL
# include "for_local.h"
#endif
using namespace std;
typedef unsigned int uint; typedef long long ll; typedef unsigned long long ull;
#define repi(_I, _B, _E) for(int _I = (_B); (_I) < (_E); ++ (_I))
#define rep(_I, _N) for(int _I = 0; (_I) < (_N); ++ (_I))
#define mkp make_pair
#define all(_X) (_X).begin(), (_X).end()
#define scani(_V) std::scanf("%d", &_V)
#define printi(_V) std::printf("%d", static_cast<int>(_V))

int const INF = 1<<29;
ll selfprod(ll x, ll y) { return x * x + y * y; }

int n;
vector<pair<int,int>> ps;
bool pred(ll len) {
	vector<bool> done(n, false);
	priority_queue<int> qs;
	qs.push(0);
	done[0] = true;
	while ( !qs.empty() ) {
		int q = qs.top(); qs.pop();
		rep(i, n) {
			if ( !done[i]
				&& selfprod(ps[q].first - ps[i].first, ps[q].second - ps[i].second) <= len * len ) {
				if ( i == n - 1 ) return true;
				qs.push(i);
				done[i] = true;
			}
		}
	}
	return false;
}

//O(n (log n)^2)
signed main() {
	cin >> n;
	rep(i, n) {
		int x, y;
		cin >> x >> y;
		ps.push_back(mkp(x,y));
	}
	ll low = 1, high = (ll)(1e9);
	rep(_, 50) {
		ll mid = low + (high - low) / 2;
		(pred(mid * 10) ? high : low) = mid;
	}
	cout << (high * 10) << endl;
	return 0;
}