input: Write a python function to handle corner cases in a string that checks for the presence of the words "heavy", "big", "light", or "small", and returns corresponding messages.
  assert handle_corner_cases('This is a Heavy box') == 'Heavy/Big objects detected!'
  assert handle_corner_cases('A small light feather') == 'Light/Small objects detected!'
  assert handle_corner_cases('Nothing special here') == 'Input not recognized!'
  assert handle_corner_cases('BIG or small') == 'Heavy/Big objects detected!'
output: def handle_corner_cases(s):
      s = s.lower()
      if 'heavy' in s or 'big' in s:
          return 'Heavy/Big objects detected!'
      elif 'light' in s or 'small' in s:
          return 'Light/Small objects detected!'
      else:
          return 'Input not recognized!'