a=gets.to_i.times.map{gets.split.map(&:to_i).sort}.sort{|a,b|b.inject(:*)<=>a.inject(:*)}
F=->a,i,l,c,m{
  return m[i] if m[i]
  return c if i>=a.size
  r=c
  (i...a.size).each{|j|
    v=a[j]
    if v[0]<l[0]&&v[1]<l[1]&&v[2]<l[2]
      q=F[a,j+1,v,c+1,m]
      r=q if q>r
    end
  }
  m[i]=r
}
p F[a,0,[10**8,10**8,10**8],0,{}]