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
ans2=(1..n).map{|i|[i,Complex(*gets.split.map(&:to_i))]}
  .combination(2).map{|(i,ic),(j,jc)|[(ic-jc).abs2,i,j]}
  .sort.find{|d,i,j|
    u(i,j)
    f(1)==f(n)
  }[0]
ans=(ans2**0.5/10).ceil*10
p ans*ans<ans2 ?ans+10:ans