def main():

  houkou = list(map(str, input()))
  kokudo_number = 1
  for shinkou in houkou:
    if shinkou == "L":
      kokudo_number = kokudo_number * 2
    else:
      kokudo_number = kokudo_number * 2 + 1
  print(kokudo_number)

if __name__ == '__main__':
  main()