#include <iostream>
#include <string>
#include <queue>
#include <stack>
#include <algorithm>
#include <list>
#include <vector>
#include <utility>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <bitset>
#include <ctime>
#include <map>
#include <unordered_map>
#include <set>
#include <unordered_set>
#include <cassert>
#include <cstddef>
#include <iomanip>
#include <numeric>

#define REP(i,n) for(int (i)=0;(i)<(n);(i)++)
#define FOR(i,a,b) for(int (i)=(a);(i)<(b);(i)++)
#define RREP(i,a) for(int (i)=(a)-1;(i)>=0;(i)--)
#define FORR(i,a,b) for(int (i)=(a)-1;(i)>=(b);(i)--)
#define MOD 1e9+7
#define PI acos(-1.0)
#define DEBUG(C) cout<<C<<endl;

typedef long long LL;
typedef unsigned long long ULL;

using namespace std;

int dx[4] = {1, 0, -1, 0};
int dy[4] = {0, 1, 0, -1};

int main(){
    int N; cin>>N;
    vector<int> cnt(10,0);
    vector<int> a(N),b(N),c(N);
    REP(i,N) {
        cin>>a[i]>>b[i]>>c[i];
        cnt[a[i]-1]++; cnt[b[i]-1]++; cnt[c[i]-1]++;
    }
    int pCnt=0,cntSum=0;
    REP(i,10){
        while(cnt[i]>=2){
            pCnt++; cnt[i]-=2;
        }
        cntSum+=cnt[i];
    }
    pCnt+=cntSum/4;
    cout<<pCnt<<endl;
}