using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; namespace lecture { class Program { static void Main(string[] args) { int N = int.Parse(Console.ReadLine()); int[] a = new int[N]; int[] b = new int[N]; int[] c = new int[N]; for (int i = 0; i < N; i++) { int[] line = Console.ReadLine().Trim().Split(' ').Select(x => int.Parse(x)).ToArray(); a[i] = line[0]; b[i] = line[1]; c[i] = line[2]; } int[] data = new int[11]; for (int i = 1; i <= 10; i++) { for (int j = 0; j < N; j++) { if (a[j] == i) { data[i]++; } if (b[j] == i) { data[i]++; } if (c[j] == i) { data[i]++; } } } int result = 0; int amari = 0; for(int i = 1;i <= 10;i++) { result += data[i] / 2; amari += data[i] % 4; } Console.WriteLine(result + amari / 4); } } }