#ifdef __MAI
#include <cassert>
#include <cctype>
#include <cerrno>
#include <cfloat>
#include <ciso646>
#include <climits>
#include <clocale>
#include <cmath>
#include <csetjmp>
#include <csignal>
#include <cstdarg>
#include <cstddef>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>

#include <ccomplex>
#include <cfenv>
#include <cinttypes>
//#include <cstdalign>
#include <cstdbool>
#include <cstdint>
#include <ctgmath>
#include <cwchar>
#include <cwctype>

#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>

#include <array>
#include <atomic>
#include <chrono>
#include <condition_variable>
#include <forward_list>
#include <future>
#include <initializer_list>
#include <mutex>
#include <random>
#include <ratio>
#include <regex>
#include <scoped_allocator>
#include <system_error>
#include <thread>
#include <tuple>
#include <typeindex>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
#else
#include <bits/stdc++.h>
#endif

using namespace std;
typedef unsigned int uint;
typedef long long int ll;
typedef unsigned long long int ull;

#define debugv(v) printf("L%d %s => ",__LINE__,#v);for(auto e:v){cout<<e<<" ";}cout<<endl;
#define debugm(m) printf("L%d %s is..\n",__LINE__,#m);for(auto v:m){for(auto e:v){cout<<e<<" ";}cout<<endl;}
#define debuga(m,w) printf("L%d %s is => ",__LINE__,#m);for(int x=0;x<(w);x++){cout<<(m)[x]<<" ";}cout<<endl;
#define debugaa(m,w,h) printf("L%d %s is..\n",__LINE__,#m);for(int y=0;y<(h);y++){for(int x=0;x<(w);x++){cout<<(m)[x][y]<<" ";}cout<<endl;}
#define debugaar(m,w,h) printf("L%d %s is..\n",__LINE__,#m);for(int y=0;y<(h);y++){for(int x=0;x<(w);x++){cout<<(m)[y][x]<<" ";}cout<<endl;}
#define ALL(v) (v).begin(),(v).end()
#define BIGINT 0x7FFFFFFF
#define E107 1000000007ll
void printbit(int u) { if (u == 0)cout << 0; else { int s = 0, k = 0; for (; 0<u; u >>= 1, k++)s = (s << 1) | (u & 1); for (; 0<k--; s >>= 1)cout << (s & 1); } }

#define TIME chrono::system_clock::now()
#define MILLISEC(t) (chrono::duration_cast<chrono::milliseconds>(t).count())

namespace {
    std::chrono::system_clock::time_point t;
    void tic() { t = TIME; }
    void toc() { fprintf(stderr, "TIME : %lldms\n", MILLISEC(TIME - t)); }
    std::chrono::system_clock::time_point tle = TIME;
#ifdef __MAI
    void safe_tle(int msec) { assert(MILLISEC(TIME - tle) < msec); }
#else
#define safe_tle(k) ;
#endif
}

template<typename T1, typename T2>
ostream& operator <<(ostream &o, const pair<T1, T2> p) { o << "(" << p.first << ":" << p.second << ")"; return o; }


random_device noize;   // noize
mt19937 mt(noize());

int rand_int(int l, int h) {
    uniform_int_distribution<> range(l, h);
    return range(mt);
}

#ifndef __MAI

namespace {
    class MaiScanner {
    public:
        template<typename T>
        void input_integer(T& var) {
            var = 0;
            T sign = 1;
            int cc = getchar_unlocked();
            for (; cc<'0' || '9'<cc; cc = getchar_unlocked())
                if (cc == '-') sign = -1;
            for (; '0' <= cc&&cc <= '9'; cc = getchar_unlocked())
                var = (var << 3) + (var << 1) + cc - '0';
            var = var*sign;
        }
        void ign() { getchar_unlocked(); }
        MaiScanner& operator>>(int& var) {
            input_integer<int>(var);
            return *this;
        }
        MaiScanner& operator>>(long long& var) {
            input_integer<long long>(var);
            return *this;
        }
    };
    class MaiPrinter {
        int stack_p;
        char stack[32];
    public:
        template<typename T>
        void output_integer(T var) {
            if (var == 0) {
                putchar_unlocked('0');
                return;
            }
            if (var < 0) {
                putchar_unlocked('-');
                var = -var;
            }
            stack_p = 0;
            while (var) {
                stack[stack_p++] = '0' + (var % 10);
                var /= 10;
            }
            while (stack_p)
                putchar_unlocked(stack[--stack_p]);
        }
        MaiPrinter& operator<<(char c) {
            putchar_unlocked(c);
            return *this;
        }
        MaiPrinter& operator<<(int var) {
            output_integer<int>(var);
            return *this;
        }
        MaiPrinter& operator<<(long long var) {
            output_integer<long long>(var);
            return *this;
        }
    };
}
MaiScanner scanner;
MaiPrinter printer;

#else
#define scanner cin
#endif

class Graph {
public:
    class adjacent {
    public:
        Graph& g;
        int id;
        adjacent(Graph& g, int id) :g(g), id(id) {}

        class iterator {
        public:
            adjacent& ref;
            int pointer;

            iterator(adjacent& ref, int p = 0) :ref(ref), pointer(p) {}
            iterator& operator ++() {
                ++pointer; return *this;
            }
            const int& operator*() const {
                int n1 = ref.g.vertex_to[ref.id].size();
                return pointer<n1 ? ref.g.vertex_to[ref.id][pointer] : ref.g.vertex_from[ref.id][pointer - n1];
            }
            int& operator*() {
                int n1 = ref.g.vertex_to[ref.id].size();
                return pointer<n1 ? ref.g.vertex_to[ref.id][pointer] : ref.g.vertex_from[ref.id][pointer - n1];
            }
            bool operator!=(const iterator& it) const {
                return it.pointer != pointer;
            }
        };
        iterator begin() { return iterator(*this, 0); }
        iterator end() { return iterator(*this, g.vertex_to[id].size() + g.vertex_from[id].size()); }
    };
    size_t n;
    vector<vector<int>> vertex_to;
    vector<vector<int>> vertex_from;

    Graph(size_t n) :n(n), vertex_to(n), vertex_from(n) {}

    void connect(int from, int to) {
        vertex_to[from].emplace_back(to);
        vertex_from[to].emplace_back(from);
    }
    void resize(size_t _n) {
        n = _n;
        vertex_to.resize(_n);
        vertex_from.resize(_n);
    }
    // for (auto to : g.vertex_adjacent(vertex_id)) な感じで使う
    adjacent vertex_adjacent(int idx) {
        return adjacent(*this, idx);
    }

    size_t degree(int v) {
        return vertex_to[v].size() + vertex_from[v].size();
    }

    void reverse_direction() {
        vertex_from.swap(vertex_to);
    }
};


/* ============ */

int n, m, kei;
int width, height;

int field[111][111];
int gx, gy;

//pair<double,int> kuri[111];
int hako[1010][3];

int hakodp[1010][1010];

Graph g(1);

int ahodfs(int u) {
    int r = 1;
    fprintf(stderr, "%d\n", u);
    for (int v : g.vertex_to[u]) {
        r = max(r, ahodfs(v) + 1);
    }
    //fprintf(stderr,"%d\n",r);
    return r;
}

int main() {
    int i, j, k;
    int x, y, z;
    int a, b, c, d;

    scanner >> n;

    g.resize(n);

    for (i = 0; i < n; ++i) {
        scanner >> x >> y >> z;
        hako[i][0] = x;
        hako[i][1] = y;
        hako[i][2] = z;
    }

    for (i = 0; i < n; ++i) {
        for (j = 0; j < n; ++j) {
            if ((hako[i][0] < hako[j][0] && hako[i][1] < hako[j][1] && hako[i][2] < hako[j][2]) ||
                (hako[i][0] < hako[j][0] && hako[i][1] < hako[j][2] && hako[i][2] < hako[j][1]) ||
                (hako[i][0] < hako[j][1] && hako[i][1] < hako[j][0] && hako[i][2] < hako[j][2]) ||
                (hako[i][0] < hako[j][1] && hako[i][1] < hako[j][2] && hako[i][2] < hako[j][0]) ||
                (hako[i][0] < hako[j][2] && hako[i][1] < hako[j][0] && hako[i][2] < hako[j][1]) ||
                (hako[i][0] < hako[j][2] && hako[i][1] < hako[j][1] && hako[i][2] < hako[j][0])) {
                g.connect(i, j);
            }
        }
    }
    //visit.resize(n);

    vector<int> rank(n,1);

    int result = 1;
    for (int u = 0; u < n; ++u) {
        queue<int> q;
        q.push(u);
        while (!q.empty()) {
            k = q.front();q.pop();
            for (int v : g.vertex_to[k]) {
                if (rank[v] < rank[k] + 1){
                    rank[v] = rank[k] + 1;
                    result = max(result, rank[v]);
                    q.push(v);
                }
            }
        }
    }

    cout << result << endl;


    return 0;
}