#include <cstdio>
#include <cstdlib>
#include <iostream>
#include <string>
#include <cmath>
#include <algorithm>
#include <vector>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <cstring>

typedef long long ll;
using namespace std;

#define mod 1000003
#define INF 10000000
#define LLINF 2000000000000000000LL

#define SIZE 10000

int main(){
    int a,b,c,n,ans=0;
    int item[101]={0},sumitem=0;
    
    scanf("%d",&n);
    
    for(int i=0;i<n;i++){
        scanf("%d%d%d",&a,&b,&c);
        
        item[a]++;
        item[b]++;
        item[c]++;
    }
    
    for(int i=0;i<=100;i++){
        ans+=item[i]/2;
        sumitem+=item[i]%2;
    }
    
    ans+=sumitem/4;
    
    printf("%d\n",ans);
    
    return 0;
}