import java.util.Arrays;
import java.util.LinkedList;
import java.util.Scanner;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class Main {
	
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		
		final int N = sc.nextInt();
		
		boolean[][] adj = new boolean[N][N];
		int[] xs = new int[N];
		int[] ys = new int[N];
		int[] zs = new int[N];
		
		for(int i = 0; i < N; i++){
			final int x = sc.nextInt();
			final int y = sc.nextInt();
			final int z = sc.nextInt();
			
			final int min = Math.min(x, Math.min(y, z));
			final int max = Math.max(x, Math.max(y, z));
			final int sum = x + y + z;
			
			xs[i] = min;
			ys[i] = sum - min - max;
			zs[i] = max;
		}
		
		int[] out_degree = new int[N];
		int[] depth = new int[N];
		
		for(int fst = 0; fst < N; fst++){
			for(int snd = 0; snd < N; snd++){
				if(fst == snd){ continue; }
				
				if(xs[fst] < xs[snd] && ys[fst] < ys[snd] && zs[fst] < zs[snd]){
					adj[fst][snd] = true;
					out_degree[fst]++;
				}
			}
		}
		
		LinkedList<Integer> queue = new LinkedList<Integer>();
		for(int i = 0; i < N; i++){
			if(out_degree[i] != 0){ continue; }
			
			queue.add(i);
			depth[i] = 1;
		}
		
		while(!queue.isEmpty()){
			final int node = queue.poll();
			
			for(int from = 0; from < N; from++){
				if(!adj[from][node]){ continue; }
				
				out_degree[from]--;
				depth[from] = Math.max(depth[from], depth[node] + 1);
				if(out_degree[from] == 0){
					queue.add(from);
				}
			}
		}
		
		System.out.println(Arrays.stream(depth).max().getAsInt());
	}
}