S = gets.chomp
counter = Array.new(26, 0)

ans = 0
an = 'A'.ord

S.each_char do |s|
  ('A'..'Z').each do |c|
    next if s == c
    cnt = counter[c.ord - an]
    next if cnt <= 1

    ans += cnt * (cnt - 1) / 2
  end

  counter[s.ord - an] += 1
end

puts ans