#include "bits/stdc++.h"
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
typedef vector<int> veci;
typedef vector<ll> vecll;
typedef vector<string> vecs;
template<class T,class U> using Hash=unordered_map<T,U>;
 
#define REP(i, a, n) for(ll i = a; i < (ll)(n); i++)
#define RREP(i, a, n) for(ll i = n-1; i >= (ll)(a); i--)
#define rep(i, n) REP(i, 0, n)
#define rrep(i, n) RREP(i, 0, n)
#define MD 1000000007
#define _SPLIT " "
 
template<class T> T read(){T a;cin >> a;return a;}
template<class T> void read(T& a){cin >> a;}
template<class T,class ...Args> void read(T& a, Args&... args){cin >> a; read(args...);} 
template<class T> void rarr(T a, int n){for(int i = 0; i < n; i++) {cin >> a[i];}}
template<class T> void write(T a){cout << setprecision(12) << a << endl;}
template<class T,class ...Args> void write(T a, Args... args){cout << setprecision(12) << a << _SPLIT; write(args...);}
template<class T> void warr(vector<T> a, const char* c = " "){cout << a[0];for(int i = 1; i < (int)a.size(); i++)cout << c << a[i];cout << endl;;}
template<class T> void warr(T a, int n, const char* c = " "){cout << a[0];for(int i = 1; i < n; i++)cout << c << a[i];cout << endl;}
void split(string s, string delim, veci& result){result.clear();string::size_type pos = 0;while(pos != string::npos){string::size_type p = s.find(delim, pos);if(p == string::npos){result.push_back(atoi(s.substr(pos).data()));break;}else {result.push_back(atoi(s.substr(pos, p - pos).data()));}pos = p + delim.size();}}
void split(string s, string delim, vecs& result){result.clear();string::size_type pos = 0;while(pos != string::npos){string::size_type p = s.find(delim, pos);if(p == string::npos){result.push_back(s.substr(pos));break;}else {result.push_back(s.substr(pos, p - pos));}pos = p + delim.size();}}
ll gcd(ll a, ll b){while(true){ll k = a % b;if(k == 0)return b;a = b;b = k;}}
ll comb(ll n, ll m){ll p=1;m=min(m,n-m);for(ll i=1;i<=m;i++){p*=n-i+1;p/=i;}return p;}

int main(void)
{
    int n;
    ll x[1000],y[1000];
    read(n);
    rep(i,n)read(x[i],y[i]);
    ll dist[1000][1000];
    rep(i,n)rep(j,n){
        ll dx=x[i]-x[j];
        ll dy=y[i]-y[j];
        dist[i][j]=dx*dx+dy*dy;
    }
    priority_queue<pair<ll,int>> q;
    q.push({0,0});
    bool vis[1000]={0};
    ll res=0;
    while(!q.empty()){
        auto fr=q.top();
        q.pop();
        if(fr.second==n-1){
            res=-fr.first;
            break;
        }
        if(vis[fr.second])continue;
        vis[fr.second]=true;
        rep(i,n){
            if(vis[i])continue;
            q.push({min(-dist[fr.second][i],fr.first),i});
        }
    }
    ll l=0,r=1e10;
    while(l<r-1){
        ll mid=(l+r)/2;
        ll f=mid*mid;
        if(f==res)write(ceil(mid/10.0)*10),exit(0);
        if(f<res)l=mid;
        else r=mid;
    }
    write(ceil(r/10.0)*10);
    return 0;
}