#include <iostream>
#include <cstdio>
#include <string>
#include <algorithm>
#include <vector>
#include <string>
#include <set>
#include <map>
#include <tuple>

using namespace std;

int g[1000][1000];
int dp[1000];
bool vis[1000];
int n;

void dfs(int u) {
	if (vis[u]) {
		return;
	}
	vis[u] = true;
	dp[u] = 1;
	for (int i = 0; i < n; i++) {
		if (g[u][i]) {
			dfs(i);
			dp[u] = max(dp[u], dp[i] + 1);
		}
	}
}

int main() {
	cin >> n;
	vector<int> x(n), y(n), z(n);
	for (int i = 0; i < n; i++) {
		cin >> x[i] >> y[i] >> z[i];
	}
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			bool ok = false;
			if (x[i] > x[j] && y[i] > y[j] && z[i] > z[j]) ok = true;
			if (x[i] > x[j] && y[i] > z[j] && z[i] > y[j]) ok = true;
			if (x[i] > y[j] && y[i] > x[j] && z[i] > z[j]) ok = true;
			if (x[i] > y[j] && y[i] > z[j] && z[i] > x[j]) ok = true;
			if (x[i] > z[j] && y[i] > x[j] && z[i] > y[j]) ok = true;
			if (x[i] > z[j] && y[i] > y[j] && z[i] > x[j]) ok = true;
			g[i][j] = ok;
		}
	}
	for (int i = 0; i < n; i++) {
		dfs(i);
	}
	cout << *max_element(dp, dp + n) << endl;
}