S = gets.chomp
MOD = 10 ** 9 + 7

dp1 = Array.new(26, 0)
dp2 = Array.new(26, 0)

S.each_char do |ch|
  i = ch.ord - 'a'.ord

  temp1 = dp1.dup
  temp2 = dp2.dup

  temp1[i] += 1
  temp2[i] += 1

  26.times do |j|
    temp1[i] += dp1[j]

    if i != j
      temp2[i] += dp1[j] + dp2[j]
    else
      temp2[i] += dp2[j]
    end

    temp1[i] %= MOD
    temp2[i] %= MOD
  end

  dp1 = temp1
  dp2 = temp2
end

puts dp2.sum % MOD