#include <algorithm>
#include <iostream>
#include <cstdio>
#include <map>
#include <numeric>
#include <cmath>
#include <set>
#include <sstream>
#include <string>
#include <vector>
#include <queue>
#include <stack>
#include <complex>
#include <string.h>
#include <unordered_set>
#include <unordered_map>
#include <bitset>
#include <iomanip>
#include <sys/time.h>
#include <tuple>
#include <random>
using namespace std;

#define endl '\n'
#define ALL(v) (v).begin(), (v).end()
#define RALL(v) (v).rbegin(), (v).rend()
#define UNIQ(v) (v).erase(unique((v).begin(), (v).end()), (v).end())

typedef long long ll;
typedef long double ld;
typedef pair<int, int> P;
typedef complex<double> comp;
typedef vector< vector<ld> > matrix;
struct pairhash {
public:
    template<typename T, typename U>
    size_t operator()(const pair<T, U> &x) const {
	size_t seed = hash<T>()(x.first);
	return hash<U>()(x.second) + 0x9e3779b9 + (seed<<6) + (seed>>2);
    }
};
const int inf = 1e9 + 9;
const ll mod = 1e9 + 7;
const double eps = 1e-8;
const double pi = acos(-1);

int n;
int x[1010], y[1010], z[1010];

vector<int> G[1010];
int num[1010];

int calc(int k) {
    if (num[k] < 0) {
        int res = 1;
        for (int i = 0; i < G[k].size(); i++) {
            res = max(res, calc(G[k][i]) + 1);
        }
        num[k] = res;
    }
    return num[k];
}

bool contain(int i, int j) {
    return x[i] < x[j] && y[i] < y[j] && z[i] < z[j];
}

int solve() {
    for (int i = 0; i < n; i++) {
        if (y[i] > z[i]) swap(y[i], z[i]);
        if (x[i] > y[i]) swap(x[i], y[i]);
        if (y[i] > z[i]) swap(y[i], z[i]);
    }
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            if (contain(i, j))
                G[j].push_back(i);
        }
    }
    memset(num, -1, sizeof(num));

    for (int i = 0; i < n; i++) {
        if (num[i] < 0)
            calc(i);
    }

    int res = 0;
    for (int i = 0; i < n; i++)
        res = max(res, num[i]);
    return res;
}

void input() {
    cin >> n;
    for (int i = 0; i < n; i++) cin >> x[i] >> y[i] >> z[i];
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << fixed << setprecision(15);

    input();
    cout << solve() << endl;
}