#include <bits/stdc++.h>
#define REP(i,n,N) for(int i=(n);i<(int) N;i++)
#define RREP(i,n,N) for(int i=N-1;i>=(int) n;i--)
#define p(s) cout<<(s)<<endl
#define DEBUG(x,y) cout<<#x<<": "<<x<<" , "<<#y<<": "<<y<<endl;
#define CK(n,a,b) ((a)<=(n)&&(n)<=(b))
#define F first
#define S second
typedef long long ll;
using namespace std;
const int inf=1e9;

vector<pair<int,pair<int,int>>> a;

int LIS1(int n){
	vector<pair<int,int>> dp;
	dp.push_back({a[0].S.F,a[0].S.S});
	REP(i,1,n){
		REP(j,0,dp.size()){
			if(dp[j].F>a[i].S.F && dp[j].S>a[i].S.S) {
				dp[j]={a[i].S.F,a[i].S.S};
				break;
			}
		}
		if(dp.back().F<a[i].S.F && dp.back().S<a[i].S.S) dp.push_back({a[i].S.F,a[i].S.S});
	}
	return dp.size();
}

int LIS2(int n){
	int dp[1010];
	REP(i,0,n) dp[i]=inf;
	REP(i,0,n){
		*lower_bound(dp,dp+n,a[i].S.S)=a[i].S.S;
	}
	return lower_bound(dp,dp+n,inf)-dp;
}

int main(){
	int N;
	cin>>N;
	REP(i,0,N){
		int tmp[3];
		cin>>tmp[0]>>tmp[1]>>tmp[2];
		sort(tmp,tmp+3);
		a.push_back({tmp[0],{tmp[1],tmp[2]}});
	}
	sort(a.begin(),a.end());
	//b.push_back({a[0][1],a[0][2]});
	REP(i,1,a.size()){
		if(a[i-1].F==a[i].F) {
			a.erase(a.begin()+i);
			i--;
		}
	}

	int ans=LIS1(a.size());
	p(ans);

	return 0;
}