#define _USE_MATH_DEFINES
#include <cstdio>
#include <iostream>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <algorithm>
#include <cmath>
#include <complex>
#include <string>
#include <vector>
#include <list>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <bitset>
#include <numeric>
#include <limits>
#include <climits>
#include <cfloat>
#include <functional>
#include <iterator>
using namespace std;

int main()
{
    int n;
    cin >> n;
    vector<vector<int> > x(n, vector<int>(3));
    for(int i=0; i<n; ++i){
        for(int j=0; j<3; ++j)
            cin >> x[i][j];
        sort(x[i].begin(), x[i].end());
    }

    vector<vector<bool> > edges(n, vector<bool>(n, false));
    vector<int> cnt(n, 0);
    for(int i=0; i<n; ++i){
        for(int j=0; j<n; ++j){
            bool ok = true;
            for(int k=0; k<3; ++k){
                if(x[i][k] <= x[j][k])
                    ok = false;
            }
            if(ok){
                edges[i][j] = true;
                ++ cnt[j];
            }
        }
    }

    queue<int> q;
    vector<int> len(n, 0);
    for(int i=0; i<n; ++i){
        if(cnt[i] == 0){
            q.push(i);
            len[i] = 1;
        }
    }
    while(!q.empty()){
        int i = q.front();
        q.pop();
        for(int j=0; j<n; ++j){
            if(edges[i][j]){
                len[j] = max(len[j], len[i] + 1);
                -- cnt[j];
                if(cnt[j] == 0)
                    q.push(j);
            }
        }
    }
    cout << *max_element(len.begin(), len.end()) << endl;

    return 0;
}