new_contents: # This program returns True if a string is a phone number and False if not
  # However, it's not very efficient
  
  
  def isPhoneNumber(text):
      if len(text) != 12:
          return False
      for i in range(0, 3):
          if not text[i].isdecimal():
              return False
      if text[3] != '-':
          return False
      for i in range(4, 7):
          if not text[i].isdecimal():
              return False
      if text[7] != '-':
          return False
      for i in range(8, 12):
          if not text[i].isdecimal():
              return False
      return True
  
  
  print('415-555-4242 is a phone number:')
  print(isPhoneNumber('415-555-4242'))
  print('Moshi moshi is a phone number:')
  print(isPhoneNumber('Moshi moshi'))
  
subject: Initialize P01_isPhoneNumber