#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using vi = vector<int>;
using vl = vector<ll>;
using vs = vector<string>;
#define endl ('\n')
inline vector<int64_t> range(int64_t stop){vector<int64_t>v(stop);iota(v.begin(),v.end(),0LL);return v;}
inline vector<int64_t> range(int64_t start,int64_t stop){vector<int64_t>v(stop-start);iota(v.begin(),v.end(),start);return v;}
inline vector<int64_t> range(int64_t start,int64_t stop,int64_t step){int s=step>0?(stop-start+step-1)/step:(stop-start+step+1)/step;if(s<=0)return {};vector<int64_t>v(s);for(int i=0;i<s;++i)v[i]=i?v[i-1]+step:start;return v;}


int main(){
    int n;
    cin >> n;
    vi C(11);
    for(auto i:range(1, 11))C[i] = 0;
    for(auto i:range(n)){
        int a;
        for(auto j:range(3)){
            cin >> a;
            C[a] += 1;
        }
    }
    int ans = 0;
    int cnt = 0;
    for(auto i:range(1, 11)){
        ans += C[i]/2;
        cnt += C[i]%2;
    }
    ans += cnt/4;
    cout << ans << endl;
    return 0;
}