Words

using System;

class Words
{
    private static int count;

    static void Main()
    {
        var arr = Console.ReadLine().ToCharArray();
        Array.Sort(arr);
        PermuteRep(arr, 0, arr.Length - 1);
        Console.WriteLine(count);
    }


    private static bool HasConsecutiveLetter(char[] word)
    {
        for (int i = 0; i < word.Length - 1; i++)
        {
            if (word[i].Equals(word[i + 1]))
            {
                return true;
            }
        }
        return false;
    }

    static void PermuteRep(char[] arr, int start, int end)
    {
        if (!HasConsecutiveLetter(arr))
        {
            count++;
        }

        for (int left = end - 1; left >= start; left--)
        {
            for (int right = left + 1; right <= end; right++)
            {
                if (arr[left] != arr[right])
                {
                    Swap(ref arr[left], ref arr[right]);
                    PermuteRep(arr, left + 1, end);
                }
            }

            var firstElement = arr[left];
            for (int i = left; i <= end - 1; i++)
            {
                arr[i] = arr[i + 1];
            }
            arr[end] = firstElement;
        }
    }

    static void Swap<T>(ref T first, ref T second)
    {
        T oldFirst = first;
        first = second;
        second = oldFirst;
    }
}