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

#define all(c) ((c).begin()), ((c).end())
#define dump(c) cerr << "> " << #c << " = " << (c) << endl;
#define iter(c) __typeof((c).begin())
#define tr(i, c) for (iter(c) i = (c).begin(); i != (c).end(); i++)
#define REP(i, a, b) for (int i = a; i < (int)(b); i++)
#define rep(i, n) REP(i, 0, n)
#define mp make_pair
#define fst first
#define snd second
#define pb push_back
#define debug( fmt, ... ) \
        fprintf( stderr, \
                  fmt "\n", \
                  ##__VA_ARGS__ \
        )

typedef unsigned int uint;
typedef long long ll;
typedef unsigned long long ull;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<vll> vvll;
typedef vector<vi> vvi;
typedef vector<double> vd;
typedef vector<vd> vvd;
typedef vector<string> vs;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const double EPS = 1e-10;

double zero(double d) {
    return d < EPS ? 0.0 : d;
}
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return true; } return false; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return true; } return false; }
#define UNIQUE(v) v.erase( unique(v.begin(), v.end()), v.end() );

template<typename T1, typename T2>
ostream &operator<<(ostream &os, const pair<T1, T2> &p) {
    return os << '(' << p.first << ',' << p.second << ')';
}

template<typename T>
ostream &operator<<(ostream &os, const vector<T> &a) {
    os << '[';
    rep(i, a.size()) os << (i ? " " : "") << a[i];
    return os << ']';
}

string toString(int i) {
    stringstream ss;
    ss << i;
    return ss.str();
}

const int MOD = 1000000007;
// a^k
ll fpow(ll a, ll k, int M) {
    ll res = 1ll;
    ll x = a;
    while (k != 0) {
        if ((k & 1) == 1)
            res = (res * x) % M;
        x = (x * x) % M;
        k >>= 1;
    }
    return res;
}

struct prepare {
	prepare() {
	    cout.setf(ios::fixed, ios::floatfield);
	    cout.precision(8);
	    ios_base::sync_with_stdio(false);
	}
} _prepare;


class UnionFind {
private:
    vi par;
    vi rank;

    int find(int x) {
        if(par[x] == x)
            return x;
        else
            return par[x] = find(par[x]);
    }

public:
    UnionFind(int n) {
        rep(i,n) {
            par.push_back(i);
            rank.push_back(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]++;
        }
    }

    bool same(int x, int y) {
        return find(x) == find(y);
    }
};

const ll INF = (1ll<<62);

ll twice(ll i) {
    return i*i;
}

int main() {
    int N;
    cin >> N;

    vector<pll> points(N);
    rep(i, N)
        cin >> points[i].first >> points[i].second;

    vector< pair<ll, int> > dists;
    rep(i, N) {
        REP(j, i+1, N) {
            ll d = twice(points[i].first - points[j].first)
                   + twice(points[i].second - points[j].second);
            dists.push_back( mp(d, i * N + j ) );
        }
    }

    sort(all(dists));

    UnionFind uf(N);
    tr(it, dists) {
        int i = it->second / N;
        int j = it->second % N;
        uf.unite(i, j);

        if(uf.same(0, N-1)) {
            // 10単位
            ll mono = (ll)(sqrt(it->first));
            int add = (10 - (mono % 10)) % 10;
            mono += add;

            // 誤差補正
            if(mono * mono < it->first)
                mono += 10;

            cout << mono << endl;

            break;
        }
    }

    return 0;
}