using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;

class TEST{
	static void Main(){
		Sol mySol =new Sol();
		mySol.Solve();
	}
}

class Sol{
	public void Solve(){
		
		int[] InDeg= new int[N];
		List<int>[] E = new List<int>[N];
		for(int i=0;i<N;i++){
			E[i] = new List<int>();
		}
		
		for(int i=0;i<N;i++){
			for(int j=0;j<N;j++){
				if(B[i][0] < B[j][0] && B[i][1] < B[j][1] && B[i][2] < B[j][2]){
					E[i].Add(j);
					InDeg[j]++;
				}
			}
		}
		
		int[] dp = new int[N];
		for(int i=0;i<N;i++) dp[i] = 1;
		
		Queue<int> Q = new Queue<int>();
		for(int i=0;i<N;i++) if(InDeg[i] == 0) Q.Enqueue(i);
		
		while(Q.Count > 0){
			var now = Q.Dequeue();
			foreach(var nxt in E[now]){
				dp[nxt] = Math.Max(dp[nxt],dp[now]+1);
				InDeg[nxt]--;
				if(InDeg[nxt] == 0) Q.Enqueue(nxt);
			}
		}
		Console.WriteLine(dp.Max());
		
	}
	int N;
	int[][] B;
	public Sol(){
		N = ri();
		B = new int[N][];
		for(int i=0;i<N;i++){
			B[i] = ria();
			Array.Sort(B[i]);
		}
	}

	static String rs(){return Console.ReadLine();}
	static int ri(){return int.Parse(Console.ReadLine());}
	static long rl(){return long.Parse(Console.ReadLine());}
	static double rd(){return double.Parse(Console.ReadLine());}
	static String[] rsa(char sep=' '){return Console.ReadLine().Split(sep);}
	static int[] ria(char sep=' '){return Array.ConvertAll(Console.ReadLine().Split(sep),e=>int.Parse(e));}
	static long[] rla(char sep=' '){return Array.ConvertAll(Console.ReadLine().Split(sep),e=>long.Parse(e));}
	static double[] rda(char sep=' '){return Array.ConvertAll(Console.ReadLine().Split(sep),e=>double.Parse(e));}
}