#include<bits/stdc++.h>
#define rep(i,a,n) for (int i = a;i < n;i++)
using namespace std;
#define MAX 11

int dp[MAX];
int main(){
    int n; cin >> n;
    rep(i,0,n){
        int a,b,c;
        cin >> a >> b >> c;
        dp[a]++;dp[b]++;dp[c]++;
    }
    int ans = 0;
    int tmp = 0;
    rep(i,0,MAX){
        ans += dp[i] / 2;
        tmp += dp[i] % 2;
    }
    ans += tmp / 4;
    cout << ans << endl;
}