using System;
using System.Collections.Generic;

class Program
{
    static void Main()
    {
        int N = int.Parse(Console.ReadLine());
        string[] S = new string[N];
        for (int i = 0; i < N; i++)
        {
            S[i] = Console.ReadLine();
        }

        HashSet<string> uniqueT = new HashSet<string>();

        for (int i = 0; i < N; i++)
        {
            for (int j = 0; j < N; j++)
            {
                if (i != j)
                {
                    uniqueT.Add(S[i] + S[j]);
                }
            }
        }

        Console.WriteLine(uniqueT.Count);
    }
}