class Yukicoder
  def initialize
    s = gets.chomp.chars
    hash = Hash.new(0)

    s.each do |ch|
      hash[ch] += 1
    end

    puts [*(1..s.size)].inject(:*) /  hash.values.map{|i| [*(1..i)].inject(:*)}.inject(:*) - 1
  end
end

Yukicoder.new