#include<bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for(int i=a;i<b;i++)






typedef vector<int> vi;
typedef vector<vi> vvi;
bool visit(const vector<vi>& g, int v, vector<int>& order, vector<int>& color) {
	color[v] = 1;
	for (int u : g[v]) {
		if (color[u] == 2) continue;
		if (color[u] == 1) return false;
		if (!visit(g, u, order, color)) return false;
	}
	order.push_back(v); color[v] = 2;
	return true;
}
bool TopologicalSort(const vector<vi>& g, vector<int>& order) {
	int n = g.size();
	vector<int> color(n);
	for (int u = 0; u < n; u++) if (!color[u] && !visit(g, u, order, color)) return false;
	reverse(order.begin(), order.end());
	return true;
}
//-----------------------------------------------------------------------------------
int N;
int X[1010], Y[1010], Z[1010];
//-----------------------------------------------------------------------------------
int cnt[1010];
int main() {
	cin >> N;
	rep(i, 0, N) scanf("%d%d%d", &X[i], &Y[i], &Z[i]);
	rep(i, 0, N) {
		int hi = max(X[i], max(Y[i], Z[i]));
		int lo = min(X[i], min(Y[i], Z[i]));
		int md = X[i] + Y[i] + Z[i] - hi - lo;

		X[i] = lo; Y[i] = md; Z[i] = hi;
	}

	vvi E(N, vi());
	rep(i, 0, N) rep(j, 0, N) if(i != j){
		if (X[i] < X[j]) if (Y[i] < Y[j]) if (Z[i] < Z[j]) {
			E[j].push_back(i);
		}
	}

	vi order;
	TopologicalSort(E, order);

	rep(i, 0, N) cnt[i] = 1;
	rep(_i, 0, N) {
		int cu = order[_i];
		for (int to : E[cu]) {
			cnt[to] = max(cnt[to], cnt[cu] + 1);
		}
	}

	int ans = 0;
	rep(i, 0, N) ans = max(ans, cnt[i]);
	cout << ans << endl;
}