#include<bits/stdc++.h>
const int N=1010; std::vector<int>g[N]; int deg[N],dp[N];
struct Box { int x,y,z; }a[N];
int main() {
    //freopen("box.in","r",stdin);
    //freopen("box.out","w",stdout);
    std::ios::sync_with_stdio(false),std::cin.tie(nullptr);
    int n; std::cin>>n;
    for(int i=1;i<=n;i++) {
        std::cin>>a[i].x>>a[i].y>>a[i].z;
        if(a[i].x>a[i].y) std::swap(a[i].x,a[i].y);
        if(a[i].x>a[i].z) std::swap(a[i].x,a[i].z);
        if(a[i].y>a[i].z) std::swap(a[i].y,a[i].z);
    }
    for(int i=1;i<=n;i++) for(int j=1;j<=n;j++) if(a[i].x<a[j].x&&a[i].y<a[j].y&&a[i].z<a[j].z) g[i].push_back(j),deg[j]++;
    std::queue<int>q;
    for(int i=1;i<=n;i++) if(!deg[i]) q.push(i),dp[i]=1;
    while(!q.empty()) {
        int u=q.front(); q.pop();
        for(auto v:g[u]) if(!(--deg[v])) dp[v]=dp[u]+1,q.push(v);
    }
    int ans=0;
    for(int i=1;i<=n;i++) ans=std::max(ans,dp[i]);
    std::cout<<ans;
    return 0;
}