using System.Collections.Generic;
using System;

public class Hello
{
    static void Main()
    {
        var n = int.Parse(Console.ReadLine().Trim());
        var s = new string[n];
        for (int i = 0; i < n; i++) s[i] = Console.ReadLine().Trim();
        getAns(n, s);
    }
    static void getAns(int n, string[] s)
    {
        var hs = new HashSet<string>();
        for (int i = 0; i < n; i++)
            for (int j = 0; j < n; j++)
            {
                if (i == j) continue;
                hs.Add(s[i] + s[j]);
            }
        Console.WriteLine(hs.Count);
    }
}