modified – Email Alerts with dynamic subject on add and edit items to the list

I want to send email alert with dynamic subject

  1. When a new item is added ,the subject of the email alert must be ‘New item added’.
  2. When i edit that item,the subject of the email should be ‘Item Modified’

How can i achieve this in a single workflow

i have checked the condition
if currentItem:created equals currentItem:modified
then email_message(a new variable) will be ‘New Item Added’
email_message will be Item Modified

Any help would be appreciated.Thanks.