#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
using namespace std;
typedef long long int ll;
typedef pair<int,int> P;
#define yn {puts("Yes");}else{puts("No");}
#define MAX_N 200005

int main() {
    int n;
    cin >> n;

    int f[11] = {};
    rep(i,n){
        int a,b,c;
        cin >> a >> b >> c;
        f[a]++; f[b]++; f[c]++;
    }

    int ans = 0;
    int cnt = 0;
    rep(i,11){
        while(f[i] >= 2){
            ans++;
            f[i] -= 2;
        }
        cnt += f[i];
    }
    
    ans += cnt / 4;

    cout << ans << endl;
    return 0;
}