#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
#define dl double
#define int long long
#define ul uint_fast32_t
#define ll int_fast64_t
#define dll long double
#define ull uint_fast64_t
#define spektar this_thread::sleep_for(chrono::milliseconds(50))
const int MAX1=1e3+5;
vector<vector<pair<dll,int>>> k(MAX1);
vector<int> vis(MAX1);
vector<dll> dis(MAX1,2e18);
priority_queue<pair<dll,int>,vector<pair<dll,int>>,greater<pair<dll,int>>> q;
void solve(){
int n;
cin >> n;
vector<array<dll,2>> kk(n);
for(auto& [a,b]:kk) cin >> a >> b;
for(int i=0; i<n; i++){
for(int j=0; j<n; j++){
k[i+1].push_back({(dll)sqrt(abs(kk[i][0]-kk[j][0])*abs(kk[i][0]-kk[j][0])+abs(kk[i][1]-kk[j][1])*abs(kk[i][1]-kk[j][1]))/2,j+1});
}
//sort(k[i+1].begin(),k[i+1].end());
}
q.push({0,1});
dis[1]=0;
while(q.size()){
dll a=q.top().first;
int b=q.top().second;
q.pop();
if(vis[b]) continue;
vis[b]=1;
for(auto& [c,d]:k[b]){
if(max(a,c)<dis[d]){
dis[d]=max(a,c);
q.push({dis[d],d});
}
}
}
dll max1=0;
for(int i=1; i<=n; i++){
max1=max(max1,dis[i]);
}
cout << fixed << setprecision(8) << max1 << endl;
}
signed main(){
//freopen("input.txt","r",stdin);
//freopen("output.txt","w",stdout);
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
int t=1;
//cin >> t;
while(t--){
solve();
}
}
