Jabber ID on the national Berland service «Babber» has a form <username>@<hostname>[/resource], where
The content of square brackets is optional — it can be present or can be absent.
There are the samples of correct Jabber IDs: firstname.lastname@example.org, email@example.com/contest.
Your task is to write program which checks if given string is a correct Jabber ID.
The input contains of a single line. The line has the length between 1 and 100 characters, inclusive. Each characters has ASCII-code between 33 and 127, inclusive.
Print YES or NO.