#include <iostream>
#include <string>
#include <vector>
#include <queue>
#include <deque>
#include <algorithm>
#include <set>
#include <map>
#include <bitset>
#include <cmath>
#include <functional>
#include <iomanip>
#define vll vector<ll>
#define vvvl vector<vvl>
#define vvl vector<vector<ll>>
#define VV(a, b, c, d) vector<vector<d>>(a, vector<d>(b, c))
#define VVV(a, b, c, d) vector<vvl>(a, vvl(b, vll (c, d)));
#define re(c, b) for(ll c=0;c<b;c++)
#define all(obj) (obj).begin(), (obj).end()
typedef long long int ll;
typedef long double ld;
using namespace std;


int main(int argc, char const *argv[]) {
  ll ans = 0;
  vll num(1000, 0);
  ll n;std::cin >> n;
  for(int i=0;i<n;i++){
    ll a, b, c;std::cin >> a >> b >> c;
    num[a]++;num[b]++;num[c]++;
  }
  for(int i=0;i<1000;i++){
    ans += num[i]/2;
    num[i] %=2;
  }
  ll cnt = 0;
  for(int i=0;i<1000;i++) cnt+=num[i];
  std::cout << ans + cnt/4 << '\n';
  return 0;
}