#define  _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <algorithm>
#include <utility>
#include <functional>
#include <cstring>
#include <queue>
#include <stack>
#include <math.h>
#include <iterator>
#include <vector>
#include <string>
#include <set>
#include <math.h>
#include <iostream> 
#include<map>
#include <iomanip>
#include <time.h>
#include <random>
#include <stdlib.h>
#include <list>
#include <typeinfo>
#include <list>
#include <set>
using namespace std;
#define LONG_INF 10000000000000000
#define MAX_MOD 1000000007
#define REP(i,n) for(long long i = 0;i < n;++i)
int dper[2000] = {};
int main() {
	int n;
	cin >> n;
	vector<tuple<int, int, int>> wow;
	REP(i, n) {
		vector<int> b;
		REP(q, 3) {
			int a;
			cin >> a;
			b.push_back(a);
		}
		sort(b.begin(), b.end());
		wow.push_back(make_tuple(b[0], b[1], b[2]));
	}
	sort(wow.begin(), wow.end());
	for (int i = 0;i < n;++i) {
		int cnt = 0;
		for (int j = i - 1;j >= 0;--j) {
			if (get<0>(wow[j]) < get<0>(wow[i]) && get<1>(wow[j]) < get<1>(wow[i]) && get<2>(wow[j]) < get<2>(wow[i]))cnt = max(cnt, dper[j]);
		}
		dper[i] = cnt+1;
	}
	int ans = 0;
	for (int i = 0;i < n;++i) {
		ans = max(ans, dper[i]);
	}
	cout << ans << endl;
	return 0;
}