Jabber ID on the national Berland service «Babber» has a form @[resource], where — is a sequence of Latin letters (lowercase or uppercase), digits or underscores characters «_», the length of is between 1 and 16, inclusive. — is a sequence of word separated by periods (characters «.»), where each word should contain only characters allowed for , the length of each word is between 1 and 16, inclusive. The length of is between 1 and 32, inclusive. — is a sequence of Latin letters (lowercase or uppercase), digits or underscores characters «_», the length of is between 1 and 16, inclusive. The content of square brackets is optional — it can be present or can be absent. There are the samples of correct Jabber IDs: mike@codeforces.com, 007@en.codeforces.comcontest. Your task is to write program which checks if given string is a correct Jabber ID.

输入描述:

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.

输出描述:

Print YES or NO.