#!/usr/bin/env python3

import array
import collections
import itertools
import sys


MAX_L = 1414213563
Point = collections.namedtuple("Point", "index x y")


def are_close(point1, point2, tol):
    dx = point1.x - point2.x
    dy = point1.y - point2.y
    return dx * dx + dy * dy <= tol * tol


def bisection(f, left, right):
    while left < right:
        mid = (left + right) // 2
        if f(mid):
            right = mid
        else:
            left = mid + 1
    return right


class UnionFind(object):

    def __init__(self, number_of_nodes, typecode="I"):
        self.par = array.array(typecode, range(number_of_nodes))
        self.rank = array.array(typecode, (0 for i in range(number_of_nodes)))

    def root(self, node):
        if self.par[node] == node:
            return node
        else:
            r = self.root(self.par[node])
            self.par[node] = r  # 経路圧縮
            return r

    def in_the_same_set(self, node1, node2):
        return self.root(node1) == self.root(node2)

    def unite(self, node1, node2):
        x = self.root(node1)
        y = self.root(node2)
        if x == y:
            pass
        elif self.rank[x] < self.rank[y]:
            self.par[x] = y
        else:
            self.par[y] = x
            if self.rank[x] == self.rank[y]:
                self.rank[x] += 1


def can_concat_all_points(n, points, ruler_length):
    uf = UnionFind(n)
    for p1, p2 in itertools.combinations(points, 2):
        if are_close(p1, p2, ruler_length):
            uf.unite(p1.index, p2.index)
    return uf.in_the_same_set(0, n - 1)


def compute_min(n, points):
    def f(x):
        return can_concat_all_points(n, points, x)
    x0 = bisection(f, 0, MAX_L)
    return (x0 + 9) // 10 * 10


def main():
    n = int(input())
    points = [Point(i, *map(int, input().split())) for i in range(n)]
    print(compute_min(n, points))


if __name__ == '__main__':
    main()