#include <bits/stdc++.h>
using namespace std;

typedef long long   signed int LL;
typedef long long unsigned int LU;

#define incID(i, l, r) for(int i = (l)    ; i <  (r); i++)
#define incII(i, l, r) for(int i = (l)    ; i <= (r); i++)
#define decID(i, l, r) for(int i = (r) - 1; i >= (l); i--)
#define decII(i, l, r) for(int i = (r)    ; i >= (l); i--)
#define  inc(i, n) incID(i, 0, n)
#define inc1(i, n) incII(i, 1, n)
#define  dec(i, n) decID(i, 0, n)
#define dec1(i, n) decII(i, 1, n)

#define inII(v, l, r) ((l) <= (v) && (v) <= (r))
#define inID(v, l, r) ((l) <= (v) && (v) <  (r))

#define PB push_back
#define EB emplace_back
#define MP make_pair
#define FI first
#define SE second
#define UB upper_bound
#define LB lower_bound
#define PQ priority_queue

#define  ALL(v)  v.begin(),  v.end()
#define RALL(v) v.rbegin(), v.rend()
#define  FOR(it, v) for(auto it =  v.begin(); it !=  v.end(); ++it)
#define RFOR(it, v) for(auto it = v.rbegin(); it != v.rend(); ++it)

template<typename T> bool   setmin(T & a, T b) { if(b <  a) { a = b; return true; } else { return false; } }
template<typename T> bool   setmax(T & a, T b) { if(b >  a) { a = b; return true; } else { return false; } }
template<typename T> bool setmineq(T & a, T b) { if(b <= a) { a = b; return true; } else { return false; } }
template<typename T> bool setmaxeq(T & a, T b) { if(b >= a) { a = b; return true; } else { return false; } }
template<typename T> T gcd(T a, T b) { return (b == 0 ? a : gcd(b, a % b)); }
template<typename T> T lcm(T a, T b) { return a / gcd(a, b) * b; }

// ---- ----

#include <stdio.h>


class UnionFind {
public:
	UnionFind(int size);
	int unite(int v, int w);
	int find(int v);
	int get_size_eq(int v);
	int get_size_part();
	virtual ~UnionFind();

private:
	int *parent;
	int *size_eq;
	int size_part;
};

UnionFind::UnionFind(int size) {
	parent = new int[size];
	size_eq = new int[size];
	for(int i = 0; i < size; i++) { parent[i] = -1; size_eq[i] = 1; }
	size_part = size;
}

int UnionFind::unite(int v, int w) {
	int fv = find(v);
	int fw = find(w);
	if(fv == fw) { return fv; }
	
	size_part--;
	int &sv = size_eq[fv];
	int &sw = size_eq[fw];
	
	if(sv < sw) {
		parent[fv] = fw;
		sw += sv;
		return fw;
	} else {
		parent[fw] = fv;
		sv += sw;
		return fv;
	}
}

int UnionFind::find(int v) {
	if(parent[v] == -1) { return v; }
	return parent[v] = find( parent[v] );
}

int UnionFind::get_size_eq(int v) {
	return size_eq[ find(v) ];
}

int UnionFind::get_size_part() {
	return size_part;
}

UnionFind::~UnionFind() {
	delete[] parent;
	delete[] size_eq;
}

// ---- ---- ---- ----

int n, x[1000], y[1000];

int main() {
	cin >> n;
	inc(i, n) { cin >> x[i] >> y[i]; }
	
	#define D ((x[i] - x[j]) * (x[i] - x[j]) + (y[i] - y[j]) * (y[i] - y[j]))
	
	UnionFind uf(n);
	inc(i, n) {
	inc(j, i) {
		if(D <= 100) { uf.unite(i, j); }
	}
	}
	
	int ans = 0;
	inc(i, n) {
	inc(j, i) {
		if(uf.find(i) == uf.find(j)) { setmax(ans, D); }
	}
	}
	
	printf("%.8f\n", (n == 0 ? 1.0 : sqrt(ans) + 2.0));
	
	return 0;
}