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]}

p (1..2e8).bsearch{|i|
  UF.clear
  l.each{|d,i,j|
    u(i,j) if i*i*100>d
  }
  f(1)==f(n)
}