#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using ll=long long;
using vll=vector<ll>;
using pll=pair<ll,ll>;


int main()
{
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
    ll N;
    vll cnt(11,0);
    cin>>N;
    for(int i=1;i<=N;++i){
        ll a,b,c;
        cin>>a>>b>>c;
        cnt[a]++;
        cnt[b]++;
        cnt[c]++;
    }
    ll ans=0,r=0;
    for(int i=1;i<=10;++i){
        ans+=cnt[i]/2;
        r+=cnt[i]%2;
    }
    cout<<ans+r/4<<endl;
}