import std.algorithm;
import std.array;
import std.conv;
import std.math;
import std.range;
import std.stdio;
import std.string;
import std.typecons;

int readint() {
    return readln.chomp.to!int;
}

int[] readints() {
    return readln.split.map!(to!int).array;
}

bool can(long len, long[][] ps) {
    int n = cast(int) ps.length;
    auto uf = new UnionFind(n);
    for (int i = 0; i < n; i++) {
        for (int j = i + 1; j < n; j++) {
            long x1 = ps[i][0];
            long y1 = ps[i][1];
            long x2 = ps[j][0];
            long y2 = ps[j][1];

            long d = (x1 - x2) ^^ 2 + (y1 - y2) ^^ 2;
            if (len * len >= d) {
                uf.unite(i, j);
            }
        }
    }
    return uf.isSame(0, n - 1);
}

long calc(long[][] ps) {
    long ans = long.max;
    long lo = 1;
    long hi = 2_000_000_000L;
    while (lo <= hi) {
        long m = (lo + hi) / 2;
        if (can(m * 10, ps)) {
            ans = min(ans, m);
            hi = m - 1;
        }
        else {
            lo = m + 1;
        }
    }
    return ans * 10;
}

void main() {
    long[][] ps;
    int n = readint();
    for (int i = 0; i < n; i++) {
        auto xy = readln.split.map!(to!long).array;
        ps ~= xy;
    }
    writeln(calc(ps));
}

class UnionFind {
    private int[] _data;

    this(int n) {
        _data = new int[](n + 1);
        _data[] = -1;
    }

    int root(int a) {
        if (_data[a] < 0)
            return a;
        return _data[a] = root(_data[a]);
    }

    bool unite(int a, int b) {
        int rootA = root(a);
        int rootB = root(b);
        if (rootA == rootB)
            return false;
        _data[rootA] += _data[rootB];
        _data[rootB] = rootA;
        return true;
    }

    bool isSame(int a, int b) {
        return root(a) == root(b);
    }

    int size(int a) {
        return -_data[root(a)];
    }
}