#include <bits/stdc++.h>
using namespace std;
using ll = long long int;
using ld = long double;
const int INF = 1 << 29;
const ll LINF = 1l << 61;
const ld PI = abs(acos(-1));
#define pq priotity_queue
#define mp make_pair
#define P pair
#define rep(i, a, b) for (ll i = (a); i < (b); i++)
#define rrep(i, a, b) for (ll i = (a); i >= (b); i--)
#define cbuf(buf, init) memset(buf, init, sizeof(buf))
#define modp(x, y) (((y) + (x) % (y)) % (y))
#define divd(x, y) (static_cast<double>(x) / static_cast<double>(y))
#define sq(x) (x) * (x)

template <ll SIZE>
class UnionFind {
public:
    using type = ll;  // must be integer type

private:
    std::array<ll, SIZE> parent_, rank_;

public:
    UnionFind()
    {
        for (ll i = 0; i < SIZE; i++) {
            parent_[i] = i;
            rank_[i] = 0;
        }
    }

    ll operator[](ll x)
    {
        if (parent_[x] == x)
            return x;
        else
            return parent_[x] = (*this)[parent_[x]];
    }

    void unite(ll x, ll y)
    {
        x = (*this)[x];
        y = (*this)[y];
        if (x == y) return;

        if (rank_[x] < rank_[y]) {
            parent_[x] = y;
        }
        else {
            parent_[y] = x;
            if (rank_[x] == rank_[y]) rank_[x]++;
        }
    }
};

ll N, X[2000], Y[2000];

/*
bool C(ll l)
{
    UnionFind<2000> uf;
    rep(i, 0, N)
    {
        rep(j, 0, N)
        {
            if (sq(X[j] - X[i]) + sq(Y[j] - Y[i]) <= sq(l)) uf.unite(i, j);
        }
    }
    return (uf[0] == uf[N - 1]);
}
*/

bool used[2000];

bool dfs(ll now, ll l)
{
    if (now == N - 1) return true;
    used[now] = true;
    rep(i, 0, N)
    {
        if (used[i] || sq(X[now] - X[i]) + sq(Y[now] - Y[i]) > sq(l)) continue;
        if (dfs(i, l)) {
            return true;
        }
    }
    return false;
}

bool C(ll l)
{
    cbuf(used, false);
    return dfs(0, l);
}

int main()
{
    //
    cin >> N;
    rep(i, 0, N) { cin >> X[i] >> Y[i]; }

    ll lb = 0, ub = 2E9;
    while (ub - lb > 1) {
        ll mid = (lb + ub) / 2;
        mid = mid / 10 * 10;
        if (mid == lb) break;

        if (C(mid))
            ub = mid;
        else
            lb = mid;
    }
    cout << ub << endl;
}