text: ﻿Username Domain Extension
  Username Domain Extension: Given a string S which is of the format USERNAME@DOMAIN.EXTENSION, the program must print the EXTENSION, DOMAIN, USERNAME in the reverse order.
  Input Format:
  The first line contains S.
  Output Format:
  The first line contains EXTENSION.
  The second line contains DOMAIN.
  The third line contains USERNAME.
  Boundary Condition:
  1 <= Length of S <= 100
  Example Input/Output 1:
  Input:
  abcd@gmail.com
  Output:
  com
  gmail
  abcd
  s=input().split('@')
  a=s[0]
  s=s[1]
  s=s.split('.')
  b=s[0];c=s[1]
  print(c,b,a,sep='\n')
  