import sys
from math import ceil

input = sys.stdin.readline


class UnionFind:
    def __init__(self, n):
        self.par = [-1] * n
        self.rank = [0] * n
        self.siz = [1] * n

    def root(self, x):
        if self.par[x] == -1:
            return x
        self.par[x] = self.root(self.par[x])
        return self.par[x]

    def is_same(self, x, y):
        return self.root(x) == self.root(y)

    def unite(self, x, y):
        if self.is_same(x, y):
            return False

        rx = self.root(x)
        ry = self.root(y)
        if self.rank[rx] < self.rank[ry]:
            rx, ry = ry, rx
        elif self.rank[rx] == self.rank[ry]:
            self.rank[rx] += 1

        self.par[ry] = rx
        self.siz[rx] += self.siz[ry]
        return True


n = int(input())
points = [tuple(map(int, input().split())) for _ in range(n)]

l = 0
r = 2 * 10**9
for _ in range(35):
    mid = ceil((l + r) / 20) * 10
    uf = UnionFind(n)
    for i in range(n - 1):
        ix, iy = points[i]
        for j in range(i + 1, n):
            jx, jy = points[j]
            if (ix - jx) ** 2 + (iy - jy) ** 2 <= mid**2:
                uf.unite(i, j)

    if uf.is_same(0, n - 1):
        r = mid
    else:
        l = mid

print(r)