#include<iostream>
#include<vector>
#include<algorithm>

using namespace std;

#define NMAX 1000

vector<int> vi[NMAX];
bool use[NMAX];
int memo[NMAX];

int search(int n);

int main(){

	int N;
	long long x[NMAX],y[NMAX],z[NMAX];
	int ans=0;

	cin>>N;
	for(int i=0;i<N;i++){
		cin>>x[i];
		cin>>y[i];
		cin>>z[i];
	}

	for(int i=0;i<N;i++){
		for(int j=0;j<N;j++){
			if(i==j) continue;
			if((x[i]>x[j]&&y[i]>y[j]&&z[i]>z[j])||(x[i]>x[j]&&y[i]>z[j]&&z[i]>y[j])||(x[i]>y[j]&&y[i]>x[j]&&z[i]>z[j])||(x[i]>y[j]&&y[i]>z[j]&&z[i]>x[j])||(x[i]>z[j]&&y[i]>y[j]&&z[i]>x[j])||(x[i]>z[j]&&y[i]>x[j]&&z[i]>y[j])){
				vi[i].push_back(j);
			}
		}
	}

	for(int i=0;i<N;i++){
		memo[i]=-1;
	}
	for(int i=0;i<N;i++){
		for(int j=0;j<N;j++) use[j]=false;
		use[i]=true;
		ans=max(ans,search(i));
	}

	cout<<ans<<endl;
}

int search(int n){

	if(memo[n]!=-1) return memo[n];
	int c=0;
	for(int i=0;i<vi[n].size();i++){
		if(!use[vi[n][i]]){
			use[vi[n][i]]=true;
			c=max(c,search(vi[n][i]));
			use[vi[n][i]]=false;
		}
	}
	memo[n]=c+1;
	return c+1;
}