#include<bits/stdc++.h>

using namespace std;
using ll=long long;
#define rep2(i, a, n) for(int i = (a); i < (n); i++)
#define rep(i, n) rep2(i,0,n)

int main(){
  cin.tie(nullptr);ios_base::sync_with_stdio(false);
  int a,b,c,n;cin>>n;
  map<int,int> map;
  for(;n>0;n--){
    cin>>a>>b>>c;
    map[a]++;
    map[b]++;
    map[c]++;
  }
  int hoge=0,cnt=0;
  for(auto itr = map.begin(); itr != map.end(); ++itr) {
      //cout<<"key="<<itr->first<<",val="<<itr->second<<"\n";
      if(itr->second%2==0){
        cnt+=itr->second/2;
      }else{
        cnt+=itr->second/2;
        hoge++;
      }
  }
  cnt+=hoge/4;
  cout<<cnt<<endl;
}