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.to!(int[]); }

alias Point = Tuple!(long, "x", long, "y");

bool can(long dist, Point[] points) {
    int n = cast(int) points.length;
    auto uf = new UnionFind(n);
    for (int i = 0; i < n; i++) {
        for (int j = i + 1; j < n; j++) {
            auto a = points[i];
            auto b = points[j];
            long d = (a.x - b.x) ^^ 2 + (a.y - b.y) ^^ 2;
            if (dist * dist >= d) {
                uf.unite(i, j);
            }
        }
    }
    return uf.isSame(0, n - 1);
}

long calc(Point[] points) {
    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, points)) {
            ans = min(ans, m);
            hi = m - 1;
        }
        else {
            lo = m + 1;
        }
    }
    return ans * 10;
}

void main() {
    int n = readint;
    Point[] points;
    for (int i = 0; i < n; i++) {
        auto xy = readln.split.to!(long[]);
        points ~= Point(xy[0], xy[1]);
    }
    writeln(calc(points));
}

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)];
    }
}