# Converting a 10 digit phone number to US format using Regex in Python 
 import re 
  
def convert_phone_number(phone):
  
  # actual pattern which only change this line
  num = re.sub(r'(?<!\S)(\d{3})-', r'(\1) ', phone) 
  return num
  
# Driver code 
print(convert_phone_number("Call geek 321-963-0612"))