#include <cstdio>
#include <iostream>
#include <string>
#include <sstream>
#include <stack>
#include <algorithm>
#include <cmath>
#include <queue>
#include <map>
#include <set>
#include <cstdlib>
#include <bitset>
#include <tuple>
#include <assert.h>
#include <deque>
#include <bitset>
#include <iomanip>
#include <limits>
#include <chrono>
#include <random>
#include <array>
#include <unordered_map>
#include <functional>
#include <complex>
#include <numeric>
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
//constexpr long long MAX = 5100000;
constexpr long long INF = 1LL << 60;
constexpr int inf = 1000000007;
constexpr long long mod = 1000000007LL;
//constexpr long long mod = 998244353LL;
const long double PI = acos((long double)(-1));

using namespace std;
typedef unsigned long long ull;
typedef long long ll;
typedef long double ld;

class UnionFind {
public:
	vector<int> Parent;
	UnionFind(int N) {
		Parent = vector<int>(N, -1);
	}
	int root(int A) {
		if (Parent[A] < 0) {
			return A;
		}
		return Parent[A] = root(Parent[A]);
	}

	long long size(int A) {
		return -(long long)Parent[root(A)];
	}

	bool connect(int A, int B) {
		A = root(A);
		B = root(B);
		if (A == B) {
			return false;
		}
		if (size(A) < size(B)) {
			swap(A, B);
		}

		Parent[A] += Parent[B];
		Parent[B] = A;

		return true;
	}

};
int main()
{
    /*
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    */

    int n; scanf("%d", &n);
    vector<ll> x(n), y(n); for (int i = 0; i < n; i++) scanf("%lld %lld", &x[i], &y[i]);
	ll lf = 0;
	ll rg = inf / 10 * 3;
	while (rg - lf > 1) {
		ll mid = (lf + rg) >> 1;
		ll l2 = mid * mid * 100;
		UnionFind uni(n);
		for (int i = 0; i < n; i++) {
			for (int j = i + 1; j < n; j++) {
				ll d = (x[j] - x[i]) * (x[j] - x[i]) + (y[j] - y[i]) * (y[j] - y[i]);
				if (d <= l2) uni.connect(i, j);
			}
		}
		if (uni.root(0) == uni.root(n-1)) rg = mid;
		else lf = mid;
	}
	cout << rg * 10 << endl;
    return 0;
}