#include <iostream>
#include <string>
#include <queue>
#include <stack>
#include <algorithm>
#include <list>
#include <vector>
#include <complex>
#include <utility>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <climits>
#include <bitset>
#include <ctime>
#include <map>
#include <unordered_map>
#include <set>
#include <unordered_set>
#include <cassert>
#include <cstddef>
#include <iomanip>
#include <numeric>
#include <tuple>
#include <sstream>
#include <fstream>
#include <chrono>

using namespace std;
#define REP(i, n) for (int (i) = 0; (i) < (n); (i)++)
#define FOR(i, a, b) for (int (i) = (a); (i) < (b); (i)++)
#define RREP(i, a) for(int (i) = (a) - 1; (i) >= 0; (i)--)
#define FORR(i, a, b) for(int (i) = (a) - 1; (i) >= (b); (i)--)
#define DEBUG(C) cerr << #C << " = " << C << endl;
using LL = long long;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<LL>;
using VVL = vector<VL>;
using VD = vector<double>;
using VVD = vector<VD>;
using PII = pair<int, int>;
using PDD = pair<double, double>;
using PLL = pair<LL, LL>;
using VPII = vector<PII>;
template<typename T> using VT = vector<T>;
#define ALL(a) begin((a)), end((a))
#define RALL(a) rbegin((a)), rend((a))
#define SORT(a) sort(ALL((a)))
#define RSORT(a) sort(RALL((a)))
#define REVERSE(a) reverse(ALL((a)))
#define MP make_pair
#define FORE(a, b) for (auto &&a : (b))
#define FIND(s, e) ((s).find(e) != (s).end())
#define EB emplace_back
template<typename T>inline bool chmax(T &a, T b){return (a < b ? a = b, true : false);}
template<typename T>inline bool chmin(T &a, T b){return (a > b ? a = b, true : false);}

const int INF = 1e9;
const int MOD = INF + 7;
const LL LLINF = 1e18;
const long double EPS = 1e-9;

const int MAX = 1010;
int N;
tuple<int, int, int> xyz[MAX];
int dp[MAX][MAX];
// [i][j] = i番目までで一番外がjのときの最大

int main() {
	scanf("%d", &N);
	REP(i, N) {
		vector<int> vec;
		int buf;
		REP(j, 3) {
			scanf("%d", &buf);
			vec.EB(buf);
		}
		SORT(vec);
		xyz[i] = make_tuple(vec[0], vec[1], vec[2]);
	}
    sort(xyz, xyz + N);
    REP(i, MAX) fill(dp[i], dp[i] + MAX, 1);
    REP(i, N) {
        REP(j, i+1) {
            int x, y, z;
            tie(x, y, z) = xyz[j];
            REP(k, j) {
                int px, py, pz;
                tie(px, py, pz) = xyz[k];
                //cout<<x<<y<<z<<endl;cout<<px<<py<<pz<<endl<<endl;
                if (px < x && py < y && pz < z) {
                    chmax(dp[i + 1][j], dp[i][k] + 1);
                }
            }
        }
    }
    int ans = 1;
    REP(i, MAX) REP(j, MAX) chmax(ans, dp[i][j]);
    cout << ans << endl;
}