UF=Hash.new{|_,k|k}
def u a,b;UF[f a]=UF[f b]end
def f c;c==UF[c]?c:UF[c]=f(UF[c])end

n=gets.to_i
l=(1..n).map{|i|[i]+gets.split.map(&:to_i)}
  .combination(2).map{|(i,ix,iy),(j,jx,jy)|[(ix-jx)**2+(iy-jy)**2,i,j]}
mn,mx=l.map(&:first).minmax
p (1..200000000).bsearch{|a|
  b=(a*10)**2
  if mn>b
    false
  elsif mx<=b
    true
  else
    UF.clear
    l.each{|d,i,j|
      u(i,j) if b>=d
    }
    f(1)==f(n)
  end
}*10