n = gets.chomp.to_i
boxes = []
for i in 0...n
  a = gets.chomp.split.map(&:to_i)
  boxes.push a
end
boxes.sort!{|a,b| a[0]*a[1]*a[2] <=> b[0]*b[1]*b[2]}
dp = []
for i in 0...n
  dp[i] = -1
end
ans = 0
def wide(a,b)
  return true if a[0]<b[0] && a[1]<b[1] && a[2]<b[2]
  return true if a[0]<b[0] && a[2]<b[1] && a[1]<b[2]
  return true if a[1]<b[0] && a[0]<b[1] && a[2]<b[2]
  return true if a[1]<b[0] && a[2]<b[1] && a[0]<b[2]
  return true if a[2]<b[0] && a[0]<b[1] && a[1]<b[2]
  return true if a[2]<b[0] && a[1]<b[1] && a[0]<b[2]
  return false
end

for i in 0...n
  box = boxes[n-1-i]
  mx = 0
  # search wider box
  for j in n-i...n
    if wide(box, boxes[j])
      if dp[j] > mx
        mx = dp[j]
      end
    end
  end
  dp[n-1-i] = mx+1
  if dp[n-1-i] > ans
    ans = dp[n-1-i]
  end
end

puts ans