#include<bits/stdc++.h>
using namespace std;
int main(){
    int n,ans=0,rem=0;
    cin>>n;
    map<int,int> m;
    for(int i=0;i<n;++i){
        vector<int> a(3);
        for(int j=0;j<3;++j)cin>>a[j];
        for(int j=0;j<3;++j){
            if(m.count(a[j])==0)m[a[j]]=1;
            else ++m[a[j]];
        }
    }
    for(auto x:m){
        ans+=x.second/2;
        rem+=x.second%2;
    }
    ans+=rem/4;
    cout<<ans<<endl;
}