output_description: Print the converted string in a line. Note that you do not need to convert any
  characters other than alphabetical letters.
input_description: A string is given in a line.
attempt: import re
  
  # Input
  words = list(input().split(" "))
  
  # Loops
  new = []
  for word in words:
      new_word = ""
      for ch in word:
          if re.match("[a-z]", ch):
              new_word = new_word + ch.upper()
          elif re.match("[A-Z]", ch):
              new_word = new_word + ch.lower()
          else:
              new_word = new_word + ch
      new.append(new_word)
  
  # Output
  for i in range(len(new) - 1):
      print(new[i], end=" ")
  print(new[-1])
  
problem_description: Toggling Cases
  
    
  
  Write a program which converts uppercase/lowercase letters to
  lowercase/uppercase for a given string.
samples: [{"input": "fAIR, LATER, OCCASIONALLY CLOUDY.", "output": "Fair, later, occasionally cloudy."}]