using System; using System.Collections.Generic; using System.IO; using System.Linq; using System.Runtime.CompilerServices; using System.Text; using System.Threading.Tasks; namespace yukicore { internal class Program { private static void Main(string[] args) { int[] items = new int[10]; string[] gets = new string[3]; int num=int.Parse( Console.ReadLine()); string[] inputs=new string[num]; int ans = 0; int sum = 0; int p = 0; int c = 0; while (true) { var tmp = Console.ReadLine(); if (string.IsNullOrEmpty(tmp)) break; p = 0; int lng = tmp.Length; if (tmp[p + 1] - 49 < -1) { items[tmp[p] - 49]++; } else { items[9]++; p++; } p++; p++; if (tmp[p + 1] - 49 < -1) { items[tmp[p] - 49]++; } else { items[9]++; p++; } p++; p++; if (p + 2 == lng) { items[9]++; } else items[tmp[p] - 49]++; } for (int i = 0; i < 10; i++) { ans += items[i] >> 1; sum += items[i] & 0x1; } sum >>= 2; Console.WriteLine(ans + sum); } } }