#include<map>
#include<set>
#include<list>
#include<cmath>
#include<queue>
#include<stack>
#include<cstdio>
#include<string>
#include<vector>
#include<complex>
#include<cstdlib>
#include<cstring>
#include<numeric>
#include<sstream>
#include<iostream>
#include<algorithm>
#include<functional>
 
#define mp       make_pair
#define pb       push_back
#define all(x)   (x).begin(),(x).end()
#define YES() printf("YES\n")
#define NO() printf("NO\n")
 
using namespace std;
 
#define int long long
//typedef    long long          ll;
typedef    unsigned long long ull;
typedef    vector<bool>       vb;
typedef    vector<int>        vi;
typedef    vector<vb>         vvb;
typedef    vector<vi>         vvi;
//typedef    pair<int,int>      P;
 
const int INF=1e+13;
const double EPS=1e-9;
 
const int dx[]={1,0,-1,0},dy[]={0,-1,0,1};

bool comp(int x,int y,int z,int xx,int yy,int zz){
	int a[] = {x,y,z},b[] = {xx,yy,zz};
	sort(a,a + 3);
	sort(b,b + 3);
	for(int i = 0;i < 3;i++){
		if(a[i] >= b[i]) return false;
	}
	return true;
}

signed main(){
	int n,x[1000],y[1000],z[1000],in[1000] = {},cnt[1000] = {};
	vector<int> G[1000];
	cin >> n;
	for(int i = 0;i < n;i++) cin >> x[i] >> y[i] >> z[i];
	for(int i = 0;i < n;i++) cnt[i] = 1;
	for(int i = 0;i < n;i++){
		for(int j = 0;j < n;j++){
			if(comp(x[i],y[i],z[i],x[j],y[j],z[j])) {
				G[i].push_back(j);
				in[j]++;
			}
		}
	}
	queue<int> que;
	for(int i = 0;i < n;i++){
		if(in[i] == 0) {
			que.push(i);
			cnt[i] = 1;
		}
	}
	while(!que.empty()){
		int v = que.front();que.pop();
		for(int i = 0;i < G[v].size();i++){
			int to = G[v][i];
			cnt[to] = max(cnt[to],cnt[v] + 1);
			in[to]--;
			if(in[to] == 0){
				que.push(to);
			}
		}
	}
	int ma = 0;
	for(int i = 0;i < n;i++) ma = max(ma,cnt[i]);
	cout << ma << endl;
	return 0;
}