#include <iostream>
#include <vector>
#include <queue>
#include <algorithm>
using namespace std;

vector<int> edge[1010];
int rest[1010];
int depth[1010];

bool contain(vector<int> a, vector<int> b) {
	do {
		if (a[0] > b[0] && a[1] > b[1] && a[2] > b[2])	return true;
	} while (next_permutation(b.begin(), b.end()));
	return false;
}

int main() {
	int n;	cin >> n;
	vector<vector<int>> dat(n, vector<int>(3));
	for (int i = 0; i < n; i++) {
		cin >> dat[i][0] >> dat[i][1] >> dat[i][2];
		sort(dat[i].begin(), dat[i].end());
	}
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			if (contain(dat[i], dat[j])) {
				edge[i].push_back(j);
				rest[j]++;
			}
		}
	}
	queue<int> q;
	for (int i = 0; i < n; i++) {
		if (rest[i] == 0) {
			depth[i] = 1;
			q.push(i);
		}
	}
	while (!q.empty()) {
		int cur = q.front();	q.pop();
		for (int i = 0; i < edge[cur].size(); i++){
			int to = edge[cur][i];
			depth[to] = max(depth[to], depth[cur] + 1);
			rest[to]--;
			if (rest[to] == 0)	q.push(to);
		}
	}
	int ret = 0;
	for (int i = 0; i < n; i++)	ret = max(ret, depth[i]);
	cout << ret << endl;
	return 0;
}