#include "bits/stdc++.h"
using namespace std;
#define rep(i,n) for(int i=0;i<n;i++)
#define REP(i,x,n) for(int i=x;i<n;i++)
#define ALL(v) (v).begin(),(v).end()
#define MP(a,b) make_pair(a,b)
typedef long long LL;
typedef pair<int, int> PI;
typedef vector<int> VI;
const LL MOD = 1000000007LL;
LL X[1000];
LL Y[1000];
struct UnionFind {
	int *par;
	int *rank;
	int size;
	UnionFind(int n) :size(n) {
		par = new int(size);
		rank = new int(size);
		rep(i, size) par[i] = i, rank[i] = 0;
	}
	void clear() {
		rep(i, size) par[i] = i, rank[i] = 0;
	}
	void unite(int x, int 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]++;
		}
	}
	int find(int x) {
		if (par[x] == x) return x;
		return par[x] = find(par[x]);
	}
	bool same(int x, int y) {
		return find(x) == find(y);
	}
};
int main() {
	int N;
	cin >> N;
	rep(i, N) {
		cin >> X[i] >> Y[i];
	}
	LL l = 0, r = 2 * 100000000;
	UnionFind U(N);
	while (r - l > 1) {
		LL m = (l + r) / 2;
		U.clear();
		rep(i, N) {
			rep(j, N) {
				if ((X[i]-X[j])*(X[i]-X[j])+(Y[i]-Y[j])*(Y[i]-Y[j]) <= (m*10)*(m*10)) {
					U.unite(i, j);
				}
			}
		}
		if (U.same(0, N - 1)) r = m;
		else l = m;
	}
	cout << r*10 << endl;
}