#include <bits/stdc++.h>
using namespace std;
#define repl(i,a,b) for(int i=(int)(a);i<(int)(b);i++)
#define rep(i,n) repl(i,0,n)
#define mp(a,b) make_pair((a),(b))
#define pb(a) push_back((a))
#define all(x) (x).begin(),(x).end()
#define uniq(x) sort(all(x)),(x).erase(unique(all(x)),end(x))
#define fi first
#define se second
#define dbg(x) cout<<#x" = "<<((x))<<endl
template<class T,class U> ostream& operator<<(ostream& o, const pair<T,U> &p){o<<"("<<p.fi<<","<<p.se<<")";return o;}
template<class T> ostream& operator<<(ostream& o, const vector<T> &v){o<<"[";for(T t:v){o<<t<<",";}o<<"]";return o;}

#define INF 21474836
#define long long long // for codeforces

int d[1000][1000];

int main(){
  int n;
  cin>>n;
  vector<int> a(n), b(n), c(n);
  rep(i,n){
    cin>>a[i]>>b[i]>>c[i];
    if(a[i]>b[i]) swap(a[i],b[i]);
    if(b[i]>c[i]) swap(b[i],c[i]);
    if(a[i]>b[i]) swap(a[i],b[i]);
  }

  fill(d[0], d[1000], -INF);
  rep(i,n) rep(j,n) if(i!=j){
    if(a[i]<a[j] && b[i]<b[j] && c[i]<c[j]) d[i][j] = 1;
  }

  rep(k,n) rep(i,n) rep(j,n) d[i][j] = max(d[i][j], d[i][k] + d[k][j]);

  int ans = 0;
  rep(i,n) rep(j,n) ans = max(ans, d[i][j]);

  cout << ans+1 << endl;

  return 0;
}