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