input: Write a Python function to verify a decimal with two decimal places.
  assert is_decimal('123.11')==True
  assert is_decimal('e666.86')==False
  assert is_decimal('3.124587')==False
output: def is_decimal(s):
      try:
          parts = s.split('.')
          if len(parts) == 2 and parts[0].isdigit() and len(parts[1]) == 2 and parts[1].isdigit():
              return True
          else:
              return False
      except:
          return False