using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;
class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    static int[] NMi => ReadLine().Split().Select(c => int.Parse(c) - 1).ToArray();
    static int[][] NMap(int n) => Enumerable.Repeat(0, n).Select(_ => NMi).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var s = ReadLine();
        var total = new int[26];
        foreach (var c in s) ++total[c - 'A'];
        var sum = new int[26];
        var ans = 0L;
        for (var i = 0; i < s.Length; ++i)
        {
            var c = s[i] - 'A';
            ++sum[c];
            if (sum[c] > 1)
            {
                ans += (long)(sum[c] - 1) * (s.Length - i - 1 - total[c] + sum[c]);
            }
        }
        WriteLine(ans);
    }
}