using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace pj11
{
    class Program
    {
        static void Main(string[] args)
        {
            int N = int.Parse(Console.ReadLine());
            int[] a = new int[(N * 3)];

            int powerup = 0;

            for(int i = 0;i < N;i++)
            {
                int[] line = Console.ReadLine().Trim().Split(' ').Select(x => int.Parse(x)).ToArray();
                a[0+(3*i)] = line[0];
                a[1+(3*i)] = line[1];
                a[2+(3*i)] = line[2];
            }

            Array.Sort(a);

            for(int j = 0;j < a.Length - 1;j++)
            {
                if(a[j] == a[j + 1])
                {
                    powerup++;
                    j++;
                }
            }
            powerup = powerup + (N * 3 - powerup * 2) / 4;
            Console.WriteLine(powerup);
        }
    }
}